Something wrong

One day I stepped of the elevator in our building and immediately noticed there must be something wrong with the ventilation. Or electrics. Or something.

Why?

I don't know... maybe because of this:

And these:

The hallway ceiling was, all-around our floor, punctured with holes. The location of what ever it was that was wrong, was obviously unknown... The hallway makes a full circle, so I walked around it, and every 2,5-3 meters there was a hole.

The next day... what ever it was, was bygones. Leaving no signs it was ever there.