Since when have ppl believed in their existence..??

I myself hav nevr believed in their existence..truly,seems like a joke to me..but i'v heard dat people have believed in ghosts since the earliest times. Since d time of the Celts, on the night before October 31st (the Celtic new year), it was thought the edges between the worlds of the living and the dead became blurred and the ghosts of the dead came back to earth. They celebrated this with a festival called Samhain (later to become Halloween).