How to Detect Hidden Cameras and Microphones

Three Methods:Initial SweepUse DarknessUse a Signal Detector

Do you feel like you're being watched? Maybe you just want to make sure your privacy is protected. Here are some different ways to locate hidden cameras and microphones.

Method 1
Initial Sweep

  1. Image titled Detect Hidden Cameras and Microphones Step 1
    Do a physical search of the premises. This involves a slow, meticulous sweep of the room or building you suspect is wired.
    • Look around for anything that seems different or out of place, such as flower arrangements, pictures on the wall out of level or in unusual areas, or lampshades that don't look normal. Check for smoke detectors you didn't add, look for a speaker that might have a camera in it.
    • Look inside flower pots, light fixtures, and other places where a microphone transmitter can easily be hidden.
    • Look under couch cushions, table tops, and shelves. Underneath shelves and table tops are excellent places for miniature cameras.
    • Look for wires that do not seem to go anywhere, such as an appliance or other familiar device. "Hardwired" (that is, not wireless) spy equipment is less common with modern technology, but is still used for permanent surveillance in commercial businesses for loss prevention.
  2. Image titled Detect Hidden Cameras and Microphones Step 2
    Listen as you walk the entire room quietly. Many small, motion-sensitive cameras make an almost inaudible click or buzz when they operate.

Method 2
Use Darkness

  1. Image titled Detect Hidden Cameras and Microphones Step 3
    Turn off the lights and look around for tiny red or green LED lights. Some microphones have "power on" indicator lights, and if the person who sets it up is careless they may fail to cover or deactivate this feature.
  2. Image titled Detect Hidden Cameras and Microphones Step 4
    While the lights are off, grab a flashlight and carefully examine all mirrors. These can be made transparent from one side so that a camera can see through, but they rely on the observer's side being darker than the area observed in order to keep the other side of the mirror reflective.
  3. Image titled Detect Hidden Cameras and Microphones Step 5
    Search for pinhole cameras in the dark. A pinhole camera might have a charge-coupled device (CCD) sitting behind a tiny opening in a wall or object. Get an empty toilet paper tube and a flashlight. Put the tube over one eye like a telescope and close your other eye. As you sweep the flashlight over the room, pay attention to any small glimmers that reflect back at you.

Method 3
Use a Signal Detector

  1. Image titled Detect Hidden Cameras and Microphones Step 6
    Buy an RF signal detector or other bug detector. If you seriously believe you are being spied on, buy an RF (radio frequency) detector and do a sweep of your room, building, or home. These portable devices are small, simple to use, and fairly inexpensive. However, there are bugs that use multiple frequencies in rapid sequence called "spread spectrum" that an RF detector will not pick up. These bugs are used by professionals and require a spectrum analyzer and an experienced technician to find.
  2. Image titled Detect Hidden Cameras and Microphones Step 7
    Use your cell phone to pick up an electromagnetic field. Place a call on your cell phone, then wave the device around where you think there might be a camera or microphone. If you can hear a clicking noise on the call, it means your phone might be interfering with an electromagnetic field.


  • Check hotel rooms.
  • If you find something, alert the authorities. Don't move or disable the camera or microphone. Act as if you hadn't noticed it, go just outside the bugged area and call your local law enforcement agency. They'll want to see evidence that the bugs were installed, and not just lying around the room.
  • Make sure that your computer's microphone and webcam (if you have one) are off or covered when not in use.
  • Wireless surveillance devices will be a bit larger, because they contain wireless transmission equipment. These devices can send information in about a 200-foot (61-meter) radius.


  • Don't let the cameras and mics know you're looking for them.
  • For stealthy sweeps, hide the RF detector and make sure it's on silent mode.

Things You'll Need

  • Empty toilet paper tube (optional)
  • Flashlight (optional)
  • A high-quality RF detector (optional)
  • Cell phone (optional)

Article Info

Categories: Self Defense | Spying