Lorraine Warren, one of the "ghostbusters" who visited the house that was named High Hopes but then rechristened The Amityville Horror, remembers that "haunted" house while publicizing the new movie also based on her long psychic career:
Although this web site is generally skeptical about ghosts, reminding people that the Bible tells us "the dead know nothing" about the living and warns us not to be misled by "deceiving spirits," my observation is that some "haunting" experiences are definitely not just confined to someone's mind. I'm not talking here about the fond memories and sense of closeness with the recently departed that sometimes comforts bereaved people; that may come from Heaven. I'm talking about the mysterious, horrific experiences that upset people who've never heard that one or more nasty things happened on that site in the past, but can believe such things happened because the site itself still feels horrible to them.
Ghosts tend to be associated with mist and vapors in foggy areas...and really evil, foul-smelling, nasty experiences, like the Amityville Horror, tend to be associated with certain forms of pollution. Green slime, putrid ooze, and feelings of panic and rage--probably including murderous rage--are very real effects that can be produced by things as mundane as septic tanks. The perception that one is levitating can be a reaction to fungal and bacterial pollution. Hallucinatory horrors are another effect many people would be likely to experience. Whether you believe in ghosts or not, walking into this kind of house is a horrifying, even nauseating experience.
The Bible describes certain houses not as "haunted" but as "leprous." These houses need to be vacated and thoroughly cleaned; moldy-colored patches need to be scrubbed and dried, and patches showing green or reddish slime need to be removed and replaced. If green or red slime reappear, the house may have to be burned.
When I was in junior high school, kids enjoyed scaring ourselves with The Amityville Horror and reassuring ourselves that it couldn't be true. After growing up and doing odd jobs that involved renovating old houses, I believe that story could very well be true. Most horror houses can be cleaned and renovated, but sometimes geological conditions make sites hopeless.
It's almost enough to make me want to watch The Conjuring, and if any local lurkers want to buy tickets I'll go, just to try to guess which of the effects are believable, natural, real...and fixable.