There was a ghost film when I was a child. A team of agents went to a building to catch ghosts, and then the ghosts patted their shoulders.

I have a date with a zombie three. In the story, Alice, a little girl in World War II, saw her parents being blown into black shadows, so she became a ghost, put it in a music box and put it in a hotel. Overnight, more than 40 people played hide-and-seek with her, and the person patted on the shoulder would become a shadow on the wall.