Of course the building is haunted, what's so unusual about that? For one thing, it's location used to be

a not the best of neighborhoods.  Back in the early 1950s, and earlier, the neighborhood was where you went to get drunk, start a fight, find a hooker and such.  Up the street, was a place where young women went for abortions.  By the way, atleast the man who preformed them was not a butcher (like the one in a nearby community) ; in that place were beds for the women to rest for about a day, and a nurse to see to them.

Anyway, several people have noted unusual things going on, like that electronic door that opens, and nobody is there.  Well, that could easily be explained since electronics does odd things.  But back in april 2020, when there was nobody else on the floor - and probably no one else on the floor/s above or the one/s below - when that stupid door swung open, why did the steady hum of the machines quit, and where did that cold air come from?  The windows don't open, and any entrances are several floors below; the nearest stairwell is behind a firewall door, and is over thataways a bit.  By the way, the windows used to be the kind that opened, but some years back, someone jumped out from like the 11th or 12th floor; there might have been another before, don't know if that person had jumped from a window a few floors up from there or not.  

It's a big building.

One of my co-workers has been there several times alone, working ot, when that door had swung open.  Don't know what had spooked her that one particular time, but she said, per that time, she turned off her computer, grabbed her purse and got out of there.

Maybe the unclean spirit who happened by was dirtier than the others who inhabit the area.  Per Matthew 12:45, foul spirits do wander from place to place, and like crooks, some are more wicked than others - some gang-bangers draw a line at harming kids, while others would stab a four year-old and laugh.

"There goeth he, and taketh with himself seven other spirits more wicked than himself, and they enter in and dwell there : and the last state of that man  is worse than the first.  Even so shall it be also unto this wicked generation."  Matthew 12:45