There are many types of non-physical entities in the Universe.
Ghosts are not the same as Dark non-physical entities, which people
tend to associate with evil. If people understand the true nature
of ghosts, there is no need to fear them:
http://www.sgforums.com/forums/1132/topics/416740
As for exorcism, it's a very real
practice (http://www.rainbowjigsaw.com/2010/03/kuan-yin-speaks-space-clearing-ghosts.html),
though what is portrayed in movies and TV are mostly over-dramatic
to entertain and scare audiences, and often only portray
ghosts as evil spirits and demons which deserve to be
destroyed. Exorcism, if done using compassionate methods,
generates positive karma for all the people involved who choose to
help the ghosts move on to the Light, one way or another.
There is a growing need for all ghosts stuck on Earth currently
to start to leave this realm within these coming years, so don't be
frightened or surprised if more and more people encounter
experiences with ghosts seeking help.
Rainbow Jigsaw of Life