Have you ever done any monster-hunting or ghost investigation? Well I have, and most of the time, not too much happens. What does happen is subtle but creepy- an unexplained sound here and a spooky cold spot there, an unshakeable feeling that something's watching you, a sudden irrational panic and so on. Whether any of this is caused by ghosts is obviously very much open to debate, but that's the type of experience you can expect to have if you experience anything at all.
Most horror movies completely ignore this fact, because a big monster with over-the-top special effects is an easier way to put some drama in the movie. There have been a few movies, though, that tell it like it is. One is “The Blair Witch Project,” of course- for most of the movie, the only evidence of a witch is some spooky noises in the background.
