A common Hindu belief holds that the spirits of men and women who died with their wishes unfulfilled, wander in the world and haunt the living instead of going to Yamapuri .
These spirits can be broadly categorised into three classes: bhuta, preta and pishacha.
A bhuta is the spirit of a man who died a violent death either by accident, suicide, or capital punishment, and has not had a proper funeral ceremony.
A preta (literally departed, deceased, dead) is the spirit of a dead person before his funeral rites are performed. However the word is more commonly applied to the spirit of a deformed or a crippled person or of one defective in some limb or organ, or of a child that dies prematurely, owing to the omission of ceremonies during the formation of the embryo. A preta is not necessarily wicked or malicious towards people.
A pishacha is a demon created by a man`s vices. It is the ghost of a liar, drunkard, adulterer, criminal, or of one who has died insane.
There are many tales and fables about these spirits, describing some as malevolent and others as good-natured and helpful.
Spirits are believed to live either at the site of their death or in secluded places. Abandoned homes and peepal trees are two favourite spots.
The Hindus also believe that if a person goes too close to a spirit, or if the services of a professional are employed, these spirits can enter human bodies. The spirit could enter through any of the nine orifices of the body. A possessed person is said to fall sick, die, be unhappy, lose his wealth, or behave oddly.
In such cases an ojha (exorcist), through mystic rites, tries to "talk" to the spirit inside and asks it to leave. If he knows the identity of the spirit, he asks its family members to perform certain ceremonies to pacify the spirit.
This system is still prevalent in some of the parts of India. Diseases and other upheavals are sometimes attributed to the fact that a deceased family member`s funeral rites have not been properly performed. To correct this, a tirthayatra is undertaken, and proper shradha is performed.
Sometimes, especially during ceremonies, a person is believed to become possessed by the spirit of a deceased family member who is either angry about something, or has come to take part in the festivities. A puja is performed to this spirit. Meanwhile the spirit is believed to be able to predict natural calamities, births and deaths through the possessed person.
Hindus wear talismans, lockets, bangles, and other adornments that are believed to have the power to protect from the gaze of spirits. The recitation of certain mantras is believed to have a similar effect.