I remember I once watch this film where these kids threw a party in an old house. It was haunted by some demon thing which possessed one who went round killing them all. I can remember they were all in fancy dress and it ends with one of the girls being put in an ambulance at the end with her friend who was possessed. Please does anyone else know this film as its doing my nut in trying to remember... thanks!

Do you know any of the actors?

I can't remember any of them, I don't even know how I got the film in the first place. It just appeared on the end of another film. The tape is now long gone

Internet sources (http://www.amazon.com/tag/horror/forum?_encoding=UTF8&cdForum=Fx2BCXSU68XSQM6&cdPage=1&cdThread=Tx2PA9U2KAB1ISF) claim that it's Killer Party from 1986.