A fire district shall elect at its first meeting and at each annual meeting thereafter a clerk, a treasurer and a collector of taxes. Such fire district may elect a chief engineer and such assistant engineers as are necessary, whether or not they are inhabitants of the district, who shall rank in the order of their election. Such officers shall hold office until the next annual meeting and until others are elected. A vacancy in any office may be filled by the prudential committee. Such district at its first meeting shall elect a prudential committee which shall consist of three persons, who shall serve for one, two and three years, respectively. Thereafter at each annual meeting a member of such committee shall be elected for the term of three years. If the fire district so votes, two additional persons may be elected to such committee for a term of one year. A vacancy in such committee may be filled at an annual meeting, or at a special meeting called for that purpose, but the selectmen of the town in which such district is located may fill a vacancy in such committee until an election by the appointment of a resident of such district. When a meeting is not held on the second Monday in January, the officers of the district may be elected at a special meeting. The officers shall be elected by ballot if demanded by a voter, and by a majority vote. (Amended 1993, No. 77, § 1.)