GHOST-TO BELIEVE OR JUST A HALLUCINATIONS

I was watching a serial named "Ek Deewana Tha." The story is about the ghost who will take a revenge who have killed him. When I was watching the serial, one thought came. Does ghost exist in the society? Why in the serials and movies are made on ghost? So, I started searching on the internet about the ghost. 

There are many references to ghosts in Mesopotamian religions – the religions of Sumer, Babylon, Assyria, and other early states in Mesopotamia. Traces of these beliefs survive in the later Abrahamic religions that came to dominate the region.Ghosts were thought to be created at time of death, taking on the memory and personality of the dead person. They traveled to the netherworld, where they were assigned a position, and led an existence similar in some ways to that of the living. Relatives of the dead were expected to make offerings of food and drink to the dead to ease their conditions. If they did not, the ghosts could inflict misfortune and illness on the living. Traditional healing practices ascribed a variety of illnesses to the action of ghosts, while others were caused by gods or demons.

The soul and spirit were believed to exist after death, with the ability to assist or harm the living, and the possibility of a second death. Over a period of more than 2,500 years, Egyptian beliefs about the nature of the afterlife evolved constantly. Many of these beliefs were recorded in hieroglyph inscriptions, papyrus scrolls and tomb paintings. The Egyptian Book of the Dead compiles some of the beliefs from different periods of ancient Egyptian history.In modern times, the fanciful concept of a mummy coming back to life and wreaking vengeance when disturbed has spawned a whole genre of horror stories and filmsThere was widespread belief in ghosts in ancient Egyptian culture The Hebrew Bible contains few references to ghosts, associating spiritism with forbidden occult activities cf. Deuteronomy 18:11. The most notable reference is in the First Book of Samuel (I Samuel 28:3–19 KJV), in which a disguised King Saul has the Witch of Endor summon the spirit or ghost of Samuel.

There are religous view as well as scientific view. The physician John Ferriar wrote "An Essay Towards a Theory of Apparitions" in 1813 in which he argued that sightings of ghosts were the result of optical illusions. Later the French physician Alexandre Jacques François Brière de Boismont published On Hallucinations: Or, the Rational History of Apparitions, Dreams, Ecstasy, Magnetism, and Somnambulism in 1845 in which he claimed sightings of ghosts were the result of hallucinations.

People who experience sleep paralysis often report seeing ghosts during their experiences. Neuroscientists Baland Jalal and V.S. Ramachandran have recently proposed neurological theories for why people hallucinate ghosts during sleep paralysis. Their theories emphasize the role of the parietal lobe and mirror neurons in triggering such ghostly hallucinations.

Some of the movies makes me believe in the ghost and the research makes me believe on those researches. I haven't see ghosts. Just a thought came researches have been done then why movies are made on ghost which makes believe on such? Does ghost really exist or its just a hallucinations? 

REFERENCES 

https://en.wikipedia.org/wiki/Ghost