I think my room has one! I can hear things in the night when everyone is asleep, and the other day i dropped on of my crystals- a sphere shaped one. It rolled under my desk, and STOPPED. I had turned around folding clothes on my bed and something touched my foot. I look down and there it is, and remember, it had stopped under my desk- the other side of the room. I'm not scared of poltergeists, but can they harm me in anyway? And can i get rid of them?