There is a camera-like light flashing on the black square.

There is a light flashing on a black square. It is a camera. If it is a red dot, it must be a pinhole camera hidden in a black square. It is recommended to cover the black box to protect yourself. Identify pinhole cameras:

1. Turn on the camera with your mobile phone and turn off the lights. Look for it with a camera lens. There will be a red light flashing where there is a pinhole camera.

2. Use professional anti-reconnaissance equipment, and use the radio frequency that detects the frequency leakage of the camera circuit to transmit wireless signals, which belongs to the radio detection mode.

3. Or use the particularity of fisheye lens to shoot a beam of light at the wall, and use optical equipment to receive and display its reflection. Because the reflection path of pinhole camera with fisheye lens is different from that of ordinary wall or mirror, pinhole camera can also be marked.

4. You can also use the mobile phone's WiFi list, because the current pinhole cameras all use the WiFi connection function. If you go to a hotel and find many strange names of WiFi devices, there are probably pinhole cameras.