I bought a house in 2005 and never asked if anyone died in it. A few strange things happened when I lived there and it creeped me out. My dad now lives in the house. When he first moved in his girlfriend claims she seen an old man in the hallway. In the last 2 weeks my dad has had the same dream that it was pitch dark and some old lady was trying to choke him. In his dream at least he thought was a dream he tried to get her off him and grabbed her hair. She turned around and bit him on the finger hard. He woke up and had teeth marks on his finger both times. I know he couldn't have bit himself because he has no teeth. The last time he said when he woke up his dog was growling and he heard a thud on the bed next to him, but he was there by himself. He has also been hearing noises in the other room, but he is awake and nobody is there. Could this be real or is he just dreaming crazy things?

First of all, dreams are real. Dreams are one way we receive information about the Universe around us. A dream that manifests physically, like something biting you in a dream and leaving a mark on your waking world physical body, is a powerful dream indeed! I had a dream scorpion sting me once. Left a scar on my ankle.

Anyway, it certainly sounds like there is some presence or energy--a spirit, maybe--which has some negative or destructive energy that is lingering about the house. It doesn't necessarily mean someone died there. Maybe they just had a really bad argument there. It might not even be a human spirit. There are some kinds of spirits that exist in our world but were never human.

Sometimes people think that spiritual activity is tied to a house, when in fact it is tied to an object they own, or the people themselves, or something else. But here, I tend to agree with you that the house itself seems to be the focus, since you noticed stuff while you were there, and now your dad is experiencing it.

How open would your dad be to doing some kind of cleansing ritual for the house? There are many such rituals, from different cultural and faith traditions. Use the one that suits your own beliefts and heritage. It's the intention you hold in the ritual, the genuineness and sincerity you bring to it, and your trust in Spirit that makes it work. The particulars--whether you use sage or lavendar or holy water or something else--are only important to the extent they help you to be clear in what you are doing.

Blessings, and good luck in getting this spirit or energy into a place of peace.