Why does the light bulb in the room flash when a person is at home?

Has this happened recently or has it always happened? When did it happen at night?

It may be the peak power consumption at night, the regional voltage is unstable, there is no voltage regulator under the light, and the current naturally fluctuates. Another possibility is that poor contact of the light bulb may also lead to this situation. If it doesn't work, change the light bulb. If not, don't turn on the light, light a flashlight, light a candle and go to bed early. There is always a way to give yourself a little confidence.