A few years ago a friend of mine rented an apartment in an old house. A year after he moved in, he started to hear footsteps from the attic above. He told us about it, and we just laughed an told him he was paranoid and that he just hallucinated it. So one friday night while we were watching movies over at his place we heard the noises too. It was definitely footstep we heard, like someone was walking slowly back and forth. We could even hear the "footsteps" moving around the attic. So we paused the movie and listened closely. The noises stopped, and we saw the rest of the movie.
Afterwards we sat and discussed what the noises could have been, and just as we were talking about it the "footsteps" reappeared. We freaked out, but decided the we should check it out. Armed with frying pans and knives from the kitchen walked towards the attic. The stairs up to the attic was in the hallway, because all of the tenants in the building had access to it. The door to the stairs had a heavy padlock plus a regular lock in the door. We unlocked the door and sneaked upstairs. We turned on the light and there was no one there. The attic was empty except for an old sofa and some mattresses, so there was really no place to hide. Scared as hell we turned off the light and locked the place.
On later occasions we heard the noises, but we never really did anything about it, we just accepted it for what it was and though it was cool to have our own "ghost pal".