Tonight, one of the the reference librarians and I were chatting in the staff area before heading out, when we heard a door close out in the main part of the library. We were closed, and the rest of the staff had been gone for at least 30 minutes. We went out to take a look around, and aside from the motion-activated lights being on in the children's room, we found nothing and no one. We stood there looking at each other.
I said, "You heard that, right?"
"And it sounded like a door closing, right?"
"It sounded exactly like a door closing, yes."
"And there's no one here, and no sign of anyone outside, correct?"
"Yep." He got a huge smile on his face, raised his fist in the air, and said, "Cool! Library ghost!"
Um, no, not cool. OK, maybe it is cool, but I am there alone several times a week, so I am, quite frankly, creeped out. And I don't know if I would be more or less creeped out if the building were old and historic rather than brand new with an open floor plan.
Yes, I guess it's possible that someone was in the building and we didn't know it and they took the opportunity to leave, but the weird thing is that the door we heard did NOT sound like the exterior doors - it sounded like one of the office doors. There are only two offices - mine, which we were sitting within view of, and the genealogy office, out in the main part of the building. We did find that office door unlocked - and it shouldn't have been - but there is no way we wouldn't have seen someone leaving the building from that area. And the exterior doors - which we never heard - were closed and locked, and someone sneaking out would not have been able to do that without making more noise. To make matters more creepy, something or someone had to have tripped the children's room lights, but I was the last one in there, the room is wide open (no places to hide), and the last patron in there had kids with them, and I saw them leave.
We checked the whole building (just one floor) and found no one. And if anyone tried to leave after we did, they would have tripped the security alarm motion sensors, and apparently that never happened, as I would have gotten a security call.
Guess I'll be re-thinking any after dark, all alone work I might have been planning....