According to Hindu Mythology, when a person die prematurely or because of the accident, murder or any tragedy than they exist in the form of evil spirit or Ghost. It means after their physical death their soul left their physical body or can say gross body and remain in the ethereal state or can attain the second body called the subtle body. They remain in this body until the remaining time of their life is complete and they attain entirely new physical body.
Many times some people have strong desire to achieve their goal but unfortunately they died before fulfilling that than also they remain in the form of Ghost. Many times Ghosts try to enter into the bodies of the other people to fulfil their desire. They generally chose the bodies of those people who have weaken themselves due to stress. This can create many problems for the people they chose. Many times they don’t try to enter but insist an individual to fulfil their desire and thus create many problems for them.
Hinduism has therefore created various Ghost busting rituals for its followers to be rescued from ghosts and the problems they cause, and to also assist the ghosts in their life journey. While doing these rituals, lot of money is extracted from the innocent people.
Actually, there is no scientific reference of the Ghost, it is just based on the believe of the people. It is advisable that one should not believe in all this and involve in the Ghost busting rituals.