I would guess later 80's maybe early, early 90's. I got the feeling it was modern day at the time. Not a Zombie movie or Halloween. Whatever it was seemed just in the house (it wasn't a decrepeted house) and you couldn't see what it was. The other scene I remember was a friend of the girl who was stabbed came to check on her, went into another room and she was killed too. Sorry I can't give a better description, Ive never seen a.movie where someone was stabbed from under the bed thru the mattress but I'm also not a movie expert
thanks for any help u can give