How to find hidden cameras in a changing room

Updated July 28, 2026 · RF Signal Detector team

A changing room is one of the few public spaces where you have an unquestioned legal expectation of privacy, and that is exactly why voyeurs target it. Cases turn up every year in retail fitting rooms, gym locker rooms, and pool changing areas, usually involving a cheap pinhole camera hidden in plain sight. The good news: the geometry of a changing stall works in your favor, because there are only a handful of places a lens can see you from, and a focused one-minute check covers all of them.

Why the check only takes a minute

A hidden camera needs power and a clear line of sight to its subject. A hotel room gives an offender dozens of placement options, which is why our guide to finding hidden cameras in a hotel room describes a longer sweep. A changing stall is different: bare walls, a hook, a bench, a mirror, maybe a vent or light. Anything watching you must sit in one of perhaps six positions, all visible from where you stand, so a minute with your eyes and your phone flashlight is genuinely enough. The check below puts the highest-probability hiding spots first, so even thirty rushed seconds cover the placements found in most real cases.

The 60-second changing room check

Do this before you hang anything up or start undressing. Keep your clothes on until you finish.

Seconds 0 to 15: trace the sightlines

Stand where you will actually undress, usually the center of the stall, and slowly turn in place. Ask one question: what can see me from here? Anything with a direct view of that spot is a candidate, and everything else can be ignored. Offenders place lenses at chest height or above, angled at the middle of the room, so this single step cuts your search area by more than half.

Seconds 15 to 35: inspect the fixtures

Check each fixture that survived the sightline pass, in this order:

• The clothes hook. The most common hiding place in prosecuted changing room cases. Commercial spy cameras are sold prebuilt inside coat hooks, sitting at chest height facing exactly where you undress. A hook with a small dark dot or pinhole in its base, a second hook mounted oddly low or high, or a hook newer than the rest of the stall deserves a close look.
• The mirror edges and frame. Before worrying about two-way glass, check the simpler threat: a pinhole camera in the frame, in a corner sticker, or in a gap between the mirror and the wall.
• Vents, ceiling corners, and light fixtures. Look up. Dark slots hide lenses well, so watch for a tiny reflective dot behind a vent slat, a smoke detector oddly close to one stall, or a hole in a ceiling tile corner.
• Holes and gaps in the walls or door. Empty screw holes, gaps in partition panels, and the space above or below the door can all conceal a lens the size of a shirt button. To know what you are looking for at that scale, see our visual guide on what a hidden camera looks like.

Seconds 35 to 60: the flashlight glint pass

Turn on your phone flashlight and sweep it slowly across every spot you just inspected, watching from just behind the light. A camera lens is curved glass, and it throws back a distinctive small glint, often bluish or purple, that flat surfaces do not. Move slowly, because the reflection only appears at certain angles, and dim the room light if you can. This one pass catches lenses too small or too recessed to spot by eye alone.

The two-way mirror check, done properly

The famous fingernail test says that if there is no gap between your fingertip and its reflection, the mirror is two-way glass. But the trick depends on where the reflective coating sits in the glass, which varies by manufacturer, so perfectly normal mirrors can fail it and some observation glass passes it. Treat it as a rough hint, not an answer.

Two checks are more reliable. First, cup your hands into a tunnel, press them against the glass, and look through while blocking as much room light as you can, adding your phone flashlight pressed near the glass. A genuine mirror shows nothing but darkness and your own reflection, while a two-way mirror lets you make out a dim space or objects behind the glass, because two-way glass only works as a mirror when your side is brighter. Second, check the mounting. A normal mirror hangs on a wall; a mirror set flush into the wall itself, with what could be a void behind it, deserves more suspicion.

What US law says about fitting room surveillance

This is a high-level overview, not legal advice, and laws vary by state. A few consistent patterns are worth knowing.

The practical takeaway: a visible dome camera in the corridor outside the fitting rooms is common and generally lawful. Anything with a view inside a stall, locker room, or shower area is a serious red flag no matter what signage the business posts.

What to do if you find a camera

If your check turns up a device, or something you strongly suspect is one, the same steps apply in a store, a gym, or a pool changing room.

1. Do not touch it. Do not unplug it, cover it, or take it with you. The device carries fingerprints, stored footage, and sometimes a live connection that can lead investigators to the person watching, and handling it damages all three.
2. Get dressed and photograph it in place. Take a close-up of the device, a wider shot showing its position in the stall, and a shot of the stall number or location. Your phone timestamps these automatically.
3. Note the details. Exact time, which stall, and anything unusual, such as a person lingering nearby.
4. Alert staff and ask them to seal the room. Ask for the manager or duty manager, and ask them to close the stall and let no one remove the device before police arrive. If staff seem dismissive or reach for the device, say clearly that you are reporting it to police and stay nearby.
5. Call the police from the scene. This is a criminal matter, not a customer service issue. Reporting while the device is still in place gives investigators their best chance.
6. Preserve your receipts and records. Your purchase receipt, gym check-in, or class booking proves you were in that room at that time, which matters for the investigation and any civil claim. Write down the names of the staff you spoke to.

If footage of you turns out to exist, ask the police about victim support services. States increasingly treat voyeurism victims as they do victims of other sexual offenses, including in how footage is handled and destroyed.

Using your phone as a pocket detector

Everything above works with eyes and a flashlight, but your phone can do more. Wireless cameras announce themselves over radio: a Bluetooth scan can flag nearby recording gadgets, and a Wi-Fi scan lists every device on a network, where cameras often appear under their manufacturer's name. If you have spotted a suspicious device on a network, our free hidden camera device checker looks up its MAC address and flags known camera brands.

RF Signal Detector packages these checks for exactly this situation: a lens finder that uses your iPhone camera to spot camera lenses, a Bluetooth scanner that identifies nearby devices and trackers, a Wi-Fi scanner for the local network, and a guided room sweep checklist so you do not have to remember any of this under stress. No app replaces your eyes, and we are direct about the limits in our honest look at whether hidden camera detector apps work, but a phone scan plus the 60-second visual check covers the realistic threats in the time a fitting room actually gives you.

Frequently asked questions

Are cameras ever legal in store fitting rooms?

Laws vary by state. Roughly a dozen US states ban cameras in dressing rooms entirely, while some others allow limited monitoring for theft prevention, usually with posted signage. Hidden recording inside a changing stall is illegal essentially everywhere, and bathrooms, locker rooms, and pool changing areas have the strongest privacy protection of all.

Does the fingernail test really detect two-way mirrors?

Not reliably. The finger-gap trick depends on how the mirror is manufactured, so it produces false alarms and false all-clears. A better check is to cup your hands against the glass, block out the light, and shine your phone flashlight through it. A real mirror shows nothing, while a two-way mirror will reveal a dim space or objects behind the glass.

What should I do if I find a hidden camera in a changing room?

Do not touch or unplug it. Get dressed, photograph the device in place from a couple of angles, note the exact stall and time, then alert staff and call the police from the scene. Keep your receipt or membership check-in record, since it proves you were there and helps investigators establish the timeline.

Can my phone actually detect hidden cameras?

Yes, within limits. A phone camera can pick up the glow of infrared night-vision LEDs, a flashlight sweep reveals lens glint, and Bluetooth and Wi-Fi scans can flag nearby recording hardware. No app catches every device, so the strongest approach combines a phone-based scan with the quick visual sweep described in this guide.