Possible.
I think that houses CAN be haunted.
Take my mom, for instance. I don't think our trailer is haunted, but I think demons can mess around with you.
My mom has a few times in the past woken up with weird scratches, and she has no clue how she got them...weird, right? We don't have rats, or large bugs in our home that may inflict such wounds...spiritual-physical harm?
I'm saying it's spirits. I think that demons and ghosts are very much for real. I also think that there are evil spirits out there with no purpose better than to torment us. Demons are different in power, remember that. A demon leaves his home (the possessed), returns and finds it cleaned (cast out the demon?), and goes back out and finds seven demons MORE powerful than he, and take over the home again.
There is a hierarchy of power out there, and reading This Present Darkness rather helped me remember that. This is a fight not of flesh and blood but of ruler, of principalities and dark powers of this world that we live in. That's our fight: against the spirit realm.
Also remember, if our eyes were opened to the spirit world around us, we might just drop dead from pure fright. Or so said God.