When I went to bed last night, I turned off the light and saw a light flashing in the air on the cupboard in my room. It is very weak. How many times have you explained it? urgent

Could be visual residue. When our eyes suddenly switch from bright environment to dark environment, because the pupil is not enlarged and the light of visual cells on the retina is not converted in time, light spots may appear in front of our eyes.

What you see after turning off the lights may be the afterimage of the light source in your room.

However, the position of the visual residual spot in your field of vision is fixed, and when you move, the spot moves with it. This is not quite consistent with what you said.

I hope it helps you. Besides, if there are no ghosts in the world, don't be afraid!