Jack-O-Lantern is a ghostly light that can be seen over swamps and marshes. It is said to be the soul of someone who died and was denied entry into Heaven and Hell. It is said that before Jack died, he chased the Devil up a tree . Jack was a mischievous person and it is said that he tied symbols of the cross around the tree. The symbols were said to be so powerful that the Devil was unable to climb down the tree, and he didn't want to fall either. When he had the Devil where he wanted, Jack made the Devil promise that he would not let him into Hell. With this done, Jack thought that he had guaranteed himself a place in Heaven that he spent the rest of his days playing tricks on people.
When he died St. Peter would not allow him to enter Heaven on account of all of his trickery, so he sent him down to Hell instead. But the gates were not open for him due to the deal that he had made with the Devil. He was left to live amongst us on Earth, in the swamps.
It is said that he liked to be cruel to children and that is why it was customary for them to wear their coats inside out. This way they could blend in with the dark and avoid the cruel clutches of Jack.