What is the creepiest, most unexplained thing you have ever experienced?

Couple years back, I was working late in my workshop, just finishing up a cabinet order. It was dead silent, not even a car passing by outside, when I clearly heard my name being called from the back storage room. I thought it was my buddy playing a prank, so I shouted back for him to quit messing around and come out. I walked over to the back, checked every corner, even behind the heavy crates, but there wasn't a soul there.

The weirdest part wasn't just the voice, but the way the air felt right after. It went ice cold, like someone had left the freezer door open, even though it was mid-July. I locked up the place and left in such a hurry I forgot my keys on the workbench. To this day, I still get goosebumps thinking about it because I know for a fact I was the only one in that building. Some things just don't have an explanation, and honestly, I don't really want one.