(a) A mayor or councilman shall forfeit his office if he (1) lacks at any time during his term of office any qualification for the office prescribed by the general law and the Constitution; (2) violates any express prohibition of Chapters 1 to 17; or (3) is convicted of a crime involving moral turpitude.
(b) A vacancy in the office of mayor or council shall be filled for the remainder of the unexpired term at the next regular election or at a special election if the vacancy occurs one hundred eighty days or more prior to the next general election.