N.J. Stat. § 40:20-35.12
Whenever the offices of all or a majority of the members of the board of chosen freeholders shall become vacant for any reason, the existence of the vacancies shall be immediately certified to the Governor by any remaining member of the board of chosen freeholders or by the county clerk. The Governor upon receipt of the certification shall forthwith fill the vacancies temporarily by appointment until successors are elected and certified for the unexpired terms at the next general election occurring not less than 60 days subsequent to the certification of the existence of the vacancies. Any appointment made pursuant to this section to fill a vacancy occurring in the next to the last year of the term and certified any time after 60 days prior to the holding of the general election, shall be made for the remainder of the term.
N.J.S. § 40:20-35.12