There are hidden cameras that store the videos on a large SD card. The perpetrator picks this up in your absence and transfers the material to his computer. Other spy cameras are wired for power and data transmission.
But there are also devices that are connected to the WLAN and stream the video material to a computer in real time. You may be able to discover these spy cameras with a WiFi scan. Fing – Network Scanner for Android app can help you.
- Install app (account is optional)
- Tap the “Search for devices” button
- scroll through the list
You will find numerous devices nearby, including of course the access point and your own smartphone. In hotels, the list could get quite long if many guests are connected to the same network.
However, the app also has a special warning function for IP cameras. You will then get a red warning message. If that happens, you need to start looking. The catch: This is only available for paying customers, but it can also be used in the free test phase.