16-533. Filling vacancy in election board by electors If the board of supervisors fails to appoint the board of election, or if all members appointed do not attend at the opening of the polls on the morning of the election, the members of the election board of the precinct present at that hour may fill the board or supply the place of an absent member thereof from the list of alternate election board members supplied by the county chairman of the political party from which another election board member is needed to maintain a political party balance. Such alternate board member is not required to be a qualified elector in the precinct for which the election board is serving.
Arizona Legal Code