is the spirit of a deceased person that for some reason or another was unable to pass on to the next life, or who's rest had been disturbed. Ghosts are neither good nor evil has there behaviour is ultimatly dictated by who they where in life and how they died.
Normally a ghost will start out confused and disorientated before realising they are dead. In some cases the trauma of death can so great thet a ghost will think that are still alive and countinue in a rountine from their lives oblivious to the fact they are dead.
The longer a ghost remains on earth the more dangerous and violent it becomes. They become so angry and upset that all they can do anymore is lashout at anyone who crosses their paths.
There are many diffrent types of ghosts,
They include:
Violent spirits
Death Omens
Death Echo
Vengeful Spirits
Generally the ghosts of violent people or people who died violent deaths. They are the most dangerous type of spirit and will attack anyone that reminds them of there deaths. Benevolent ghosts also have the potential to turn violent as a result of staying on earth to long or emotional stress
Death Omens
While they apear violent and intimidating they are not dangerous ghosts but rather trying to warn people who may be murdered by the person who killed them. They are tied to the earth because they wish to find out who killed them.
Death Echo
An ocasional byproduct of murder by a ghost. They are spirits who are trapped in an endless cycle of their murder and the pain of death. An Echo can be shocked out of the cycle and then pass on if they are confronted or calmed by a person they have an emotional link with.
Vengeful Spirits
While dangerous and volent these ghosts are not evil in nature. They are simply seeking vengeance for a wrong committed against them or a loved one. This can range from exposing the truth to attacking those involved with the wrongdoing untill they feel the score has been settled. On the rare ocaision they can still be attached to their body such as with Calie in Bedtime stories who had grown frustrayted that her father did not know the truth about her death and that he would not let her pass on.
Ghost sickness is spread by a specific class of spirit known as the Buruburu. First the victim must have physical contact with the ghost's body or the body of another victim of ghost sickness. However, not everyone is susceptible to the virus. The only people who can contract it are those that share a specific personality that matches the original killer of the Buruburu.
Symptoms
Ghost sickness first appears as nightmares and subtle signs of irrational fear. The fear gets greater and greater as the illness progresses. Soon after the initial symptoms, wounds mirroring those the originating ghost received while alive appear on the victim without an apparent cause. As the ghost sickness progresses further the victim feels queasiness that degenerates into vomit. Toward the ending stages the vomiting degenerates further into vomiting blood. At the final climax of the illness the victim will experience intense terror that will cause a fatal heart attack.
The Cure
The cure for ghost sickness is to destroy the ghost who began spreading the virus. Buruburu can be "scared to death" by recreating its original death.
What is the Buruburu?
The Buruburu is a spirit form first catagorized and documented by the Japanese in the Edo period. The Buruburu are Ghosts born of fear after dying in a terrifying manner. It spreads it, inflicting people who have terrorized other people with fear, also known as the Ghost Sickness.
great job. I'm a fan of ghosts by the way 
nice one bro, find mire info here; [topic=2015861]DRIVING OUT GHOSTS[/topic]
Am afraid of ghost,alien etc..