N.J. Stat. § 26:3-14
If a township committee in a township having a population of not more than twenty thousand inhabitants, which is subject to the provisions of this subdivision of this article, shall fail to appoint a physician member within ten days after the death, removal or resignation of any physician, or after the expiration of his term, the State department may appoint a physician as a member of the local board, who shall hold his office for the term of three years from the time of his appointment by the State department and until his successor shall be appointed.
If a physician shall not be appointed either by the township committee or by the State department, the members of the township committee and the assessor shall constitute the local board of the township and shall continue to constitute the board until the appointment shall be made.
N.J.S. § 26:3-14