"You don't believe in ghosts, do you?" is probably one of the most common questions I get when discussions happen to turn to the paranormal. And to this I must answer "no".
I don't believe in ghosts, just as I don't believe that I am a human being living in Sweden. It is not a matter of belief or dis-belief. I know there are experiences which one may - for the lack of a better word - call ghostly encounters. The question should rather be: what are ghosts.
There are a few suggestions. The most popular idea, and the one commonly found in popular newspapers and magazines, is that a ghost is the disembodied soul of a deceased person (or animal). The argument usually runs along the lines that the deceased either has been wronged and seeks revenge or has done wrong and seeks amence. Or, or even and, that the deceased has not realised that he/she/it is dead, wandering aimlesly through a "reality" between the living and the dead, perhaps doing things he/she/it did when alive. The spectre just need a gentle push in the right direction by someone able to see it and give the necessary help.
Others argue that some ghosts simply are re-plays of what once happened in that particular space. This re-play can be viewed by a visitor perceptive enough. This may result in some pretty weird effect as a enuine spectre does not have a will of its own - it down not interact with the reality. If a particular scene has been imprinted upon the environment -it is this scene one will see repeated. If a particular door was open at the time of "recording" and is closed at the time of replay the apparition will seem to walk right through the closed door. If the building has sunk half a meter since the recording, the apparition will be walking half a meter above the floor!
Another view on this automated behaviour was put forward by Myers, who thought that they were "dreams dreamt by the deceased persons whose phantasms appear. Myers 1889-90)
Related to this view is the opinion that it is the living who recieve emotional imprints from the environment and through themselves, "the medium", recreats the scenario. The living recreats a personality from the memories of the environment. Many ghosts will act in a more concious way than those who are just a replay the past. This ghost has been created through sub-concious interaction between the living and the imprint placed by the dead.