Eat, drink and be scary

'Tis now the very witching time of night,
When churchyards yawn and hell itself breathes out
Contagion to this world.
William Shakespeare

All Hallows’ Eve is derived from the Celtic Night of the Dead. The Celtic people divided the year by four major holidays. The festival observed at this time was called Samhain (pronounced Sah-ween); the Celts believed that this night, the souls of those who had died this past year were traveling their lonely way to the other world, and thus, for those few hours, division between this mortal world and the world to come all but vanished. Ghosts could walk the world and did.  All Hallows’ Eve and All Souls’ Day

From ghoulies and ghosties
And long-leggedy beasties
And things that go bump in the night,
Good Lord, deliver us!

Scottish

That Hallowe’en the hill noises sounded louder than ever, and fire burned on Sentinel Hill as usual; but people paid more attention to the rhythmical screaming of vast flocks of unnaturally belated whippoorwills which seemed to be assembled near the unlighted Whateley farmhouse. After midnight their shrill notes burst into a kind of pandaemoniac cachinnation which filled all the countryside, and not until dawn did they finally quiet down. Then they vanished, hurrying southward where they were fully a month overdue. What this meant, no one could quite be certain till later. None of the country folk seemed to have died—but poor Lavinia Whateley, the twisted albino, was never seen again.

H.P. Lovecraft

You can read The Dunwich Horror short story by clicking the link.