I was hoping to have this one ready at Halloween, but long hours at work and the need to look after the wife while she deals with a herniated disk means it is a month late.
Night of the Demons (1988), in which a disparate group of moron teenagers throwing a party on Halloween night in an abandoned funeral home that has a tragic history, conjure up more than they can deal with when they decide to conduct a séance.
This one is my longest review ever. At over 32,000 words in length, it took me well over 2 hours just to proofread it. I advise packing a lunch if you attempt to read it.