The Uninvited (1944)
 

I don't think I had heard of this flick until recently, but I caught it on TCM recently and absolutely loved it. If you liked The Haunting (1963) and The Innocents (1961), check this one out.

http://www.imdb.com/title/tt0037415/

I second the recommendation. Saw this in a film class and liked it a lot. I wish they'd release a DVD, though. I want to see it again!

Sam