Let me start by saying; no, I do not believe in ghosts. Though if they were real, you should have no reason to fear them.
1: If the ghost is hanging out in your house, it is probably someone you know, and they are just hanging out or watching over you.
2: Ghosts can't hurt you.
3: Even if they could, they wouldn't, because if a ghost accidentally killed you, then you would turn into a ghost and it would become REALLY awkward.
*Edit:
1.5: If it wasn't someone you know then they would either be actively trying to get rid of you or would have already left.