When I was a child, one of my very favorite books was The Ghost in the Swing by Janet Patton Smith. It was the one I checked out the most at my library, and even when I didn't choose to check it out during a particular library visit, I often stopped by its location on the shelf, just to see if it was there. I read it to my girls last year as one of our Halloween reads, and when I discovered an additional book by the same author that I'd never read, I picked up a used copy (both are currently out of print), and we read it together this year. My older daughter (11 years old at the time) enjoyed it, but my other daughter, two years younger, did not connect with it as much. It is about a teenager whose parents are having marital difficulties, and they send her to visit her strange and reclusive aunt while they try to sort things out. The house next door turns out to be haunted by a ghost who is able to lure people into the time period (the 1940s) in which she lived. It's creepy and interesting, but the characters were fairly two-dimensional, and in the end we found we all much preferred The Ghost in the Swing.
The Twisted Room by Janet Patton Smith (Lauren Leaf, 1983)