When staying in a hotel, I met something that is easy to flash red. This is a camera.

It may be a fire sensor. Ask the hotel manager for details. The general camera is not like this. The infrared ray used by the camera to fill the light is invisible to the human eye.

Stay in a hotel to prevent candid photos. After entering the room, you can turn off the lights and close the curtains to make the room as dark as possible. Then turn on the phone, turn on the video, record every place in the room, and record all the places you think may be photographed. If there is a red light in the mobile phone video, it means there is a sneak shot device. Because of the lack of light, the camera equipment will supplement infrared rays, which can be captured by the mobile phone camera!