When he crawled out he was a mental wreck

It's kind of funny that I had The Legend of Hell House (1973) movie by the player for months just waiting to be watched and I had the Richard Matheson novel Hell House on the shelf in line to be read for months as well. I didn't connect the dots before. They are the same damn thing. Old school horror of a haunted house that is being investigated by both a scientist and a psychic. It's pretty creepy and atmospheric.