Shamus, n.: A shamus is a guy who takes care of handyman tasks around the temple, and makes sure everything is in working order. A shamus is at the bottom of the pecking order of synagog functionaries, and there's a joke about that: middle of a service, "Oh, Lord, I am nobody!" The cantor, not to be bested, also cries out, "Oh, Lord, I am nobody!" The shamus, deeply moved, follows suit and cries, "Oh, Lord, I am nobody!" The rabbi turns to the cantor and says, "Now look who thinks he's nobody!"
Arthur Naiman