Help ID this movie.

I was trying to figure out the name of a movie for my girlfriend last night and had no luck (which means I probably haven’t seen it). She said it’s rated R and was in the theaters about 2 years ago.
At first all she told me was, “It’s about a lady who died, and now she lives in the floors” as well as telling me that the majority of the movie takes place in this lady’s house, and the little bit that’s not in her house is in the neighbor’s house. (BTW she’s pretty sure of that part, since most movies I came up with, she rejected based on the fact that they weren’t filmed in a single house).
Later she went on to say that it’s about a husband and wife who live in that house. He goes out of town. At some point someone breaks in and tries to kill her, the neigbors somehow figure out what’s going on, and I guess the killer turns out to be her husband . (Since I don’t know the plot, I’m really not sure if that was a spoiler or not, sorry if it was). Anyways, she also mentioned that inside the floors, or in the basement, or under the house was of some significance. She also said it’s not a “scary movie” and if she had to guess in would be in the Drama section. Any ideas???

Could be What Lies Beneath.