New Jersey Statutes Title 40A. Municipalities and Counties 40A § 9-11

Whenever a county or municipal officer, who is required to be a resident shall cease to be a bona fide resident of the county or municipality, as the case may be, or whenever the resignation of any such officer shall have been accepted by the proper authority, his office shall immediately be deemed to be vacant. The county or municipality, by the proper authority, shall thereupon proceed to fill the vacancy in the manner prescribed by law.

A nonresident of any municipality may hold office as counsel, attorney, engineer, health officer, auditor or comptroller of such municipality and no such office shall be deemed vacated by a change of residence of any such person.