chair moved by it's self

Ok here is my ghost story, basically we was decorating the bathroom and needed a dinning room chair to stand on to get to the high parts , we finished and left the chair in there, later i woke up that night to go to the toilet, i noticed the door was shut as i aproached the bathroom , i pushed on the door something on the otherside was blocking it, i could feel it was the chair we used for decorating, i did'nt go in and left it till morning for someone else to go in, aparently when they went in the morning the door was wide open and the chair was in the place we left it?.