I'm guessing this is Michigan's name for the elected, partisan office that is in charge of doing party business within a precinct, right? I think a lot of people are assuming you mean a caucus delegate. Most states call what you're describing something else; here it's "Precinct Committee Officer."
The office and roles vary quite a bit from state to state. In IL there is a precinct committeeman elected (except in Cook) during the general primary. The elected committeemen also may serve as delegates to the county and state conventions with a weighted voted equal to the number of ballots cast for their party at the preceding primary. They also may meet to fill vacancies, though for multi-county jurisdictions this function goes to the county chairs elected at the county conventions. Cook county elects committeemen by ward and township rather than by precinct, but otherwise they function in a similar fashion.
It's an excellent way to meet your political leaders and have an impact on elections.
