There is a woman in it, and then I will stare at it 10 seconds, and then look at the ceiling. What will I see? I dare not try. ..

What is scientifically explained is a kind of "visual residue". You can try. It's not scary at all. I'm a pupil, so I'm not surprised. I'm just a little weird. I can tell you the image: it was a woman on the ceiling, and soon disappeared, so I couldn't see her face clearly. She's not a ghost anyway. Give you a picture:

I hope you can adopt it! Really not scary! Great!