If the chair thing happens often I'd set up a video camera. I'd like to see the chair move.
Yeah, that's what I would do as well. Funny thing is, if the chair did move, people would say it was fake. Did you happen to see the Ghost Hunters show this past season? They did one show at a lighthouse up in New England where they set up a camera in the top floor. When the guy who was sitting there got up and left, the chair that he sat in suddenly moved several inches. That was freaky.... and I would hope the show wouldn't fake something like that.