no, no, that's not a dumb question at all! in fact, i just asked my boyfriend what he thought it was and he said "sewer man".
![Stick out tongue :p :p](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
what you described is a plumber! plumbers fix pipes, water works, and everything related drainage. basically, think of mario, haha.