I dont necessarily believe or disbelieve in them but I'll make my story as short as possible. I was remodeling an apartment and had to carry the old furnishings through a 3 story staircase to the basement level to toss in the dumspter. The staircase is barren and the light bulb dim so if anyone comes in you can immediately see sunlight and/or hear the door slam shut from the springs they had. I had just come from the top level and reached the 1st level when THROUGH my headphones and music I hear; Hey what are you doing? I paused and thought what the fudge there's security here? I looked around, no cameras no speakers. Then I hear; who are you? I answer. So I climb up a staircase looking for anyone but nobody's there. I put my headphones in again and start walking back down, then again I hear; you didnt answer what are you doing here? This time I immediately take out my headphones and answer, and then AGAIN he asks but who are you? Thats when i was like wtf is goin on because he kept asking the same questions and i heard him the same volume wether or not my headphones were in. I just went to throw away whatever it was I was carrying some old blinds or somethin. And then i went to talk to the manager of the apartments who i got along with well and i casually brought up the old security guard questioning me. She laughed and asked me what i was talking about, i kinda explained what happened and she just went pale, told me an older gentleman with dementia or soemthin like that had died in that staircase when he fell. I didn't freak out, but it definitely weirded me out using that staircase, i took the slow elevator for a while.