It Is Possible that Our House Is Haunted (or that We Have Mice)

The last couple of days, there has been this weird-ass scratching, scurrying noise in the walls and ceiling of my bedroom. It doesn't seem to happen through the day, but at night it's really loud and almost constant. It's either a ghost or a shit-ton of mice. I know the mice are more likely, but I think I'll pretend it's a haunting to make my life a little more interesting. Somebody get me some salt rounds.