Last night I read The Ghost of Crutchfield Hall by Mary Downing Hahn.
This one was a little intense for me - considering it was MG. The descriptions of the dead girl were almost too much.
I never could have read a book like this when I was a kid. Would have had nightmares for life.
I felt that way about the only MDH mystery I've read--All the Lovely Bad Ones. I think it would have freaked me out as a child. She's very successful, though, and I've heard her books are really popular with kids (as 12y.o.writer's comments seems to confirm!) Maybe in this post-Goosebumps/horror movie age kids are harder to scare.