Last year (more like, last month) my colleague shared an eerie experience:

He was chatting with another two of my colleagues, the time was about 1AM.

Suddenly, they heard a woman's voice, calling for a guy's name, from a secured room far from their place.

No one was working in that secured room.

After it went to silent for a moment,

the woman's voice appeared right inside the emergency stairway, which was locked as well. (yah, this is Malaysia, I guess, locked for what?)

They quickly left the place.