Let me start by saying I'm the biggest skeptic regarding anything paranormal, religious, spiritual, etc... But after this experience, I'm questioning that stance. I tend bar on Saturday nights in a small social club in my town. The building and the club have been in existence since 1918. Rumor has it that this club used to be a hangout for many Mafia types and associates. Needless to say, I'm sure this club has a lot of history and can only imagine what has occurred within its wall over the years.
Anyway, the club is a long narrow building that has 2 floors. On the ground floor is the bar then in the back is a kitchen and there is a small office in the very front of the building. Upstairs is a small storage area then one large meeting hall that is sometimes used for parties, etc. To leave, you go through a door into a hall that is about 10 feet long and is between the small office and the stairs to the meeting hall. At the end of this short hall is the door to outside.
This past Saturday I had closed the bar and had finished all of the cleaning, counting, etc. Everyone had left and I had locked the outside door. After shutting everything off, including all TVs and the jukebox, I went to leave. It was 2:15 am. I went through the first door into the hall which is where the alarm system is and when I did I could hear, quite plainly, old time (like 20's era) piano music playing and a very strange voice singing/talking. It was very easy to hear but muffled, like it was in the other room, so I couldn't quite make out the words.
First thing I did was open the door to the bar thinking the jukebox came on but it was quiet in there. I then looked out of the outside door window thinking maybe a car was sitting out there with the radio on but no one was even close. At first I thought it was coming from the small office on the other side of the wall but as I listened it sounded like it was coming from upstairs and there is a small vent on the hallway ceiling.
So then, being somewhat creeped out, I go to set the alarm. Normally when all is ready, it will say DISARMED: READY TO ARM. When I looked at it it did say that for a second but it keep randomly flashing to COMM ERROR. If a door was left open, it would say DOOR # whatever. Then you would have to check that door and that code would go back to DISARMED: READY TO ARM. After flashing a few times it stopped and finally read DISARMED: READY TO ARM. I was able to set it and leave. The only time I had seen it do that was there was a party and a few balloons were left and the ventilation system was blowing them around and was picked up by the interior motion detectors. To me this suggests that something inside of the club was moving. I wasn't about to go find out.
As I said, I'm very skeptical when hearing anything of this nature and am usually always able to find a logical explanation. Also, this is the first experience I've ever had of this nature in my 40 years. I'm kind of at a loss on this one and I was pretty shook up afterward.