I don’t know about the novel “Poltergeist,” but “The Exorcist” is based upon an actual event that occurred in Mount Rainier, Maryland. See — http://blogs.weta.org/boundarystones/2014/01/14/real-story-behind-exorcist
I first heard about this before the movie came out from a priest at college when I was working in the college library, I don’t recall how the topic came up, but he knew the senior priest in the story. 30 years later, I met a Catholic Deacon and the topic of exorcism came up and I mentioned Fr. Kaiser telling me about the real ‘Exorcist’ incident, and discovered that this Deacon knew the younger priest. And he said that the younger priest has “been haunted” by the memory of that event ever since.
I believe in demonic possession, but I do NOT believe that people with psychic gifts from God are automatically demonic, that determination is based, in my view, on do they use their gift for good or evil. See my earlier post # 59 on 1st Cornithians, Ch 12.
But you DO believe that 'psychic gifts' are FROM God??