What is flashing above the hotel room?

There is a flashing red light on the ceiling of the hotel room, which is a smoke detector set by the fire alarm system. It is used to prevent fire. You can relax, because the hotel room is a private space and the hotel is not allowed to install probes. If there is too much smoke in the room, the smoke detector will give an alarm. When the room is about to catch fire, the fire sprinkler will automatically start sprinkling water to extinguish the fire, ensuring the safety of every customer.