Real Paranormal Activity

I was at a friends house when he told me there were devil dolls. I was thinking what's a devil doll but oh well. So later that night we hear banging on the walls; that was around 1:30 AM. I fell asleep on the couch and he went to bed.

Later the next morning we hear the same banging. So I had a crazy idea - a home made Ouija board. All we did was write letters on it and used a coin to slide to the letters. At first he was sliding it to mess with me but later it really did move on its own. His brother was freaked when that happened. So later on I left.

I come back a couple days later and we decide to use it again. but after we used it for a couple minutes my friend fell backwards. I asked him "What happened"? and he said something hit him. so I'm still puzzled. Is it a demon or a evil spirit? Help!