TV series example of the word

The Big Bang Theory Season 4, Episode 22
...and eat with the janitor.

The Big Bang Theory Season 11, Episode 15
Hans the janitor.

The Big Bang Theory Season 1, Episode 13
Here, I am janitor. In former Soviet Union, I am physicist.

The Big Bang Theory Season 1, Episode 13
So may I introduce the third-floor janitor, the lady from the lunch room and...

The Big Bang Theory Season 7, Episode 11
I have two PhDs yet somehow I'm the janitor