I watched this movie on Netflix instant around a year ago. It was a group of guys renovating either a hospital or an asylum. Something like that. While they're renovating it scary stuff keeps happening and they think that it's haunted. At the end it turns out that there wasn't a ghost doing it, but that it was actually one of the workers who was possessed. He kills the others and then goes into a room with pictures all over the walls. (Might not have been possessed. It was one of those endings where you were sort of left wondering).
That sounds like "Session 9" with David "CSI Miami" Caruso....
Session 9 Trailer (http://www.youtube.com/watch?v=LsxkRNvEbhM#ws)
That's it! Thanks so much!
Happy to be of service. (tips hat)