Any ideas why I keep hearing sounds when I’m alone at work?

I’d start with the boring building checks: vents, pipes, a radio in another room, outside traffic, or sound carrying through a doorway. Stores can have odd acoustics, and a short whistle or voice-like noise can be hard to place when everything else is quiet.

If it happens again, note the time, location, what was running nearby, and whether anyone else heard it. A recording might help document the sound, but it won’t by itself tell you where it came from.

Could be a mix of background noise and being tired at the end of a shift. I wouldn’t jump straight to a paranormal explanation. Ask a coworker to check the spots with you and see whether the same sounds happen under similar conditions.

Two isolated incidents don’t establish what caused them, but keep an eye on whether this starts happening more often or outside work too. If it continues, feels frightening, or comes with other changes in how you’re feeling or hearing, consider talking with a healthcare professional. That’s a sensible check, not a judgment about what you experienced.