Ghosts are an important part of folklore in India in general and Maharashtra in particular.  Fairy tales, both old and new often use the concept of ghosts. References to ghosts may be often found in mythological and Vedic literature in India. The Hindu Garuda Purana has detailed information about ghosts. Although the evidence for ghosts is largely anecdotal, the belief in ghosts throughout history has remained widespread and persistent.
Ghost is a non-material embodiment or essence of an organism, especially of human being. This term is sometimes used virtually as a synonym for soul or spirit. It is believed that the persons who die unnatural deaths or die with unfulfilled wish/desire remain on earth as ghosts. More frequently, however the term ghost is applied to an apparition, usually of a dead person, that varies in apparent solidly from a mere fog-like mass to perfect replica of the person. The common word for ghost in Marathi is bhoot. There are different terms to different types of ghosts at various regions of Maharashtra. A female ghost is often referred as Hadal.  Ghost of an unmarried young man is called Munjya.

Ghosts: Unsatisfied souls

The belief in ghosts as souls of the unsatisfied departed persons may be closely related to the ancient Hindu concept of animism, which attributed souls to everything in nature, including human beings, animals, plants, rocks, etc. that souls were seen as the creature within that animated the body. If a man lives and moves, it can only be because he has a little man who moves him. The man inside the man, is the soul.It is widely held that the soul is an exact reproduction of the body in every feature, even down to clothing the person wore. As such the person who believes in ghosts often imagine them as he is seeing the people around him; which also depends upon the upbringing of the person and culture of the community to which the person belongs to. What a ghost is said to look like and consist of is quite dependent on preconceptions made by the society to which person belongs to.

Imagination

In folklore, ghosts are often found in desolate stretches of road or fields around villages, unused houses, wells and places, at crematoriums and graveyards, on peepal or banyan or other similar trees. Curious aspects of ghosts are, that their feet are said to be turned around, ghosts do not have heads, their eyes are located on their chests, they do not cast shadows, one can’t see their reflections, ghosts can enter any place or room closed or open; strong wind blows and chill is experienced in their presence etc. Surprisingly the ghosts can be seen only by a few but not by all, and particularly not by skeptics. Ghosts in folk tales are almost always malicious. In modern stories and films, ghosts often take on more friendly appearances.

Reason: Limitation of human perception

What is a ghost? We can conceive two types: one that is sham or a figment of imagination and the other that results from mental illness. The sham ghost may be because of the pretense or deceit, or nurtured impressions, or may be due to strong suggestions or it may be just sensory illusion. Modern critics of “eyewitness ghost sightings” suggest that limitations of human perception and ordinary physical explanations can account for such sightings; for example, air pressure changes in a home causing doors to slam, or lights from a passing car reflected through a window at night. There is an innate tendency to recognize patterns in random perceptions, is what some skeptics believe causes people to believe that they have seen ghosts. Reports of ghosts “seen out of the corner of the eye” may be accounted for by the sensitivity of human peripheral vision. Peripheral vision is very sensitive and can easily mislead, especially late at night, when the brain is tired and more likely to misinterpret sights and sounds. A person’s belief that a location is haunted may cause them to interpret mundane events as confirmations of existence of ghosts.

Sound is thought to be another cause of supposed sightings. Frequencies lower than 20 hertz are called infra sound and are normally inaudible, but scientists have concluded that infra sound can cause humans to experience bizarre feelings in a room, such as anxiety, extreme sorrow or even the chills.

Carbon monoxide poisoning, which can cause changes in perception of the visual and auditory systems, was recognized as a possible explanation of the existence of ghosts. Another potential explanation of apparitions is that they are hallucinations. Some researchers, have speculated that changes in geomagnetic fields could stimulate the brain’s temporal lobes and produce many of the experiences associated with ghost sightings.

Harm caused by this belief

The belief in ghosts often leads to bizarre thoughts and behavior. They become obsessed with the idea and often remain in tension and under fear. The rumors are spread and the   place where the ghost is supposed to be seen will either be deserted completely or become a place of worship. Sometimes the noisy ghost will start disturbing the objects in the place or lit a fire which often leads to phenomenon of Bhanamati (Poltergeist) . A related phenomenon is the poltergeist, literally a ‘noisy spirit’ that manifests itself by moving and influencing objects, though a widespread view today is that these occurrences are either fraudulent or manifestations of the psychic energy of, particularly, adolescent girls or someone intended to have attention from the family. This often leads to loss of property. Summoning or exorcising the shades of the departed is an item of belief and religious practice for spiritualists and practitioners of ritual magic. These  claims of ‘clearing the ghosts from the area’ are proven frauds.

What MANS is doing
MANS has challenged the ghost sighting and is ready to award a large sum to those who can prove the existence of ghost through scientific tests. ANS activists often undertake the awareness programs to inhibit the fear of ghosts  where it is more prevalent. ANS has published printed materials in this regard which explains the phenomenon critically and scientifically.