I used to live in an apartment building that used to be a hospital. It was a two story house, two apartments downstairs, two upstairs. As you walked in the front door, there was one apartment to the left, and one to the right. The staircase was directly in front of the door. My apartment was directly at the top of the stairs. A walkway ran parallel to the staircase, and there was a rickety bannister to supposedly keep you from falling onto the staircase if you lost your balance, and there was a fourth apartment at the end of the walkway.
I lived there about a month before I noticed anything strange. One night, I had a party, and myself and my guests began to hear someone pacing in the hallway outside my door. We checked repeatedly and never found anyone in the hallway. The front door was very thin, not meant to keep anyone out, really, it could easily be broken down if you really wanted to, I could have broken it down and I weighed 85-90 pounds at that time! My back door was in the kitchen, that door lead into an attic, which had an outside door to a wooden fire escape. After my guests left, I heard someone trying the back door. I called the police as the doors were very flimsy and although the police responded quickly, they found no one but the door was open, one of the officers actually borrowed a screwdriver to repair either the lock or the knob, it was pulled from the frame or the door, I don't recall now.
For quite a while afterwards, I heard the pacing in the hallway and coincidently found that the building used to be a hospital. The old-timer who told me this also told me there was once a fire in the building. After living there a few years, my carpet became so old and worn it would tear from the weight of the furniture on it, and the landlord had it pulled up and replaced. When the carpet layer came and tore up the old carpet, we discovered scorching to the wooden floorboards right beside my front door, and marks where a woodburning stove had stood. There was also a hatch in the wall, which was also scorched badly so it wasn't a patch from repairing the fire damage. We did not open it, but it was directly behind the wood stove. I finally came to the conclusion that possibly a spirit was pacing beside the stove, probably fretting about a loved one being in the hospital. This would go on night and day, and at times I would hear the pacing and have the daylights scared out of my by a real live person knocking on my door! Unfortunately, the old timer who gave my this information about my home was also deceased by that time, so I was never able to ask him about it again. At first it was frightening, I thought I was being stalked or something! It then became puzzling, but after a while I got used to it and it no longer bothered me. Not to mention, finding the stove marks on the floor really kind of explained things for me, the house was always very very cold in the winter, so if a stove had stood there, that would be where one would linger. I just feel kind of sorry now for whoever it is/was pacing the floor, and wonder what they were waiting for?