Ghost, Goblins, and Ghouls

Could there be a scientific explanation for the things that go bump in the night? People who believe in the supernatural refuse to believe those that don't and visa versa. Could both be right?

String Theory has opened the possibility of other dimensions, besides the four we know about (three physical dimensions, plus time.) In fact, according to String Theory there are eleven dimensions. Our perceptions of reality are based in the three dimensions we understand. How would we appear to a race of two dimensional people? Picture this, a two dimensional world would look like a sheet of paper. Stick your finger through that paper. From the two dimensional view, we would look like a cross section of that finger, nothing more.

There are a number of explanations for ghosts. Some people who are highly susceptible to suggestion will see things that aren't there. There is thought that many sightings are the result of visual stimuli that are produced in a dreamlike state. Occasionally, there is a supernatural event that can't be rationalized or understood. Why can't a ghost be an interdimensional event? How would beings from dimensions beyond our comprehension appear to us?

Why is it so easy to believe in ghosts, yet not in a scientific explanation for them?