How To Tell If A Smoke Detector Is A Hidden Camera

The best way to tell if a smoke detector is a hidden camera is if you notice a camera lens on the device itself. Additionally, you can use an RF signal scanner or your smartphone camera to detect IR waves and confirm. 

You can also check your Wi-Fi network or look for suspicious wires or connections. Unfortunately, these are very case-specific, and you’ll need to use multiple such methods to verify further. 

Things to Know

  • The best way to tell is by spotting a camera lens or using your smartphone to detect infrared waves.
  • Using An RF signal scanner or checking the Wi-Fi network is somewhat effective. However, it will only work if the hidden camera is connected to a Wi-Fi or cellular network. 
  • You can also check for any odd-looking wires. Unfortunately, this won’t apply to wire-free or wireless cameras.
  • Location matters as well. For instance, if you find a smoke detector in a bathroom, it’s probably a hidden camera. 
  • You can test its smoke-detection features. However, this isn’t entirely reliable as an actual smoke detector might have been modified to include a hidden camera.
  • Ultimately, you can take it apart and see if there’s an actual camera inside.

How to Tell A Smoke Detector From a Hidden Camera

There are several methods you can use to figure out if the smoke detector is real or fake. These include:

  1. Looking for a Camera Lens
  2. Search for a Warning Label or Open it Up
  3. Look for Any Out-Of-Place Wires and Connectors
  4. Consider the Location of the Smoke Detector
  5. Check Cell Phone Reception Near the Smoke Detector
  6. Scan The List of Devices Connected to the Wi-Fi Network
  7. Use A Smartphone Camera to Check for Infrared Lights
  8. Use an RF Signal/Anti-Spy Detector Device
  9. Check the Ability to Detect Smoke 

This mostly relates to indoor hidden cameras. If you’re looking to hunt cameras outdoors, check out this article on how to hide a camera outdoors.

1. Check for a Camera Lens 

Hidden security cameras need a clear line of sight to record. As such, the camera lens has to be exposed or hidden behind a glass-like material. 

So, look for a small, glassy hole in the smoke detector. You can shine a bright light into dark vents to make it easier to spot.

You can buy special gadgets that help spot camera lenses much more easily.

2. Check for Any Labels or Try Opening it Up

If possible, you might also take down the smoke detector and check the inside for any warning labels. Sometimes, the device will mention it’s a fake smoke detector on the enclosure itself. 

You can also try to open it up. If you manage to do so, check for any unusual circuits or ports that might accommodate a battery, MicroSD card slot, or a camera lens.

3. Look for Any Out-Of-Place Wires and Connectors

Another aspect of hidden cameras is that they need a source of power and a method to store/transfer video. 

Most hidden cameras will have extra wires that supply power and transfer data. So, if you find wires inside a smoke detector, it could cause concern. 

However, this method isn’t reliable by itself. Some smoke detectors can be hardwired. 

Conversely, the camera could be wireless or wire-free. Therefore, use other methods as well to confirm your suspicions. 

4. Take Note of the Location Where the Smoke Detector is Installed

Smoke detectors are usually set up in areas that might pose a fire hazard. This includes hallways and living areas. 

Additionally, they’re usually positioned above the ceiling. This makes it easier to detect rising smoke.

So if you find smoke detectors installed somewhere it doesn’t belong (say, a bathroom or vertically on a wall), there’s a good chance it’s fake. 

However, like the previous method, this step isn’t exactly foolproof.

5. Check Cell Phone Reception Near the Smoke Detector

Hidden cameras that use a cellular network can create interference with your phone. 

As such, you can use your smartphone to check for this. Take a phone call and check the audio reception near the smoke detector.  

Get as close as possible to the smoke detector. Then, listen in for unusual audio delays, static, or other forms of interference. 

Try this out several times. If you get consistent results when close to the smoke detector, there’s probably a hidden camera inside. 

Thinking of picking up a cellular camera? Check out this article on the best 4G LTE security cameras

6. Scan the List of Connected Devices in the Wi-Fi Network

This method only works when you can log into the same network as the hidden camera. 

So, if you can connect to the suspected Wi-Fi network, you can use a service, such as Fing, to check for hidden cameras. Check for device names such as “IP-Camera” or look for brand names such as “Arlo, Wyze, etc..).

However, the device might be renamed differently. Also, this feature only works for Wi-Fi cameras. 

So unless you can get an exact match, combine this with other methods to confirm. 

7. Use Smartphone’s Camera to Detect IR Waves

Most hidden cameras will switch over to infrared when it’s pitch black. While doing so, they will turn on the infrared lights for visibility. 

You can leverage this feature to check for hidden cameras inside your smoke detector. However, your smartphone’s camera (front or back) should have the ability to detect infrared waves.

So try turning off all the lights. Then, open up the camera on your smartphone and point it at your smoke detector. 

If you notice purple or white light, you can be certain it’s infrared radiation coming from a hidden camera. 

Want to learn how infrared works? Check out this article to learn more about how infrared night vision works in a security camera

8. Use an RF Signal Detector

You can use a dedicated RF signal detector to verify if there’s a security camera inside. 

This method is similar to taking a phone call near the camera. However, an RF detector is much more accurate and could even recognize Wi-Fi cameras.

Also, you can use this device to check quickly for any other hidden cameras.

9. Check the Ability to Detect Smoke

If any of the methods you carried out previously couldn’t help, you can try to trigger the alarm. 

You can light a match under the device and blow it out. Then, hold it to the smoke detector and see if the alarm turns on. 

Alternatively, you can also use an aerosol spray designed to test smoke detectors. 

If the device does detect smoke and start sounding the alarm, reset it by unplugging or taking out the batteries. 

However, this device could also contain a hidden camera and an actual smoke detector. Therefore, combine this step with other techniques to verify. 


To spot a hidden camera in a smoke detector, you can use several methods. That said, the most effective options are using an RF signal scanner, catching infrared waves, or finding an actual camera lens inside. 

You can also test the smoke detection feature. However, the device could have an actual smoke sensor coupled with the camera. 

In any case, keep your eyes sharp, trust your instincts, and don’t hesitate to investigate. Your privacy is worth the effort.

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