N.J. Stat. Ann. § 40:20-35.13

Any person appointed by the board of chosen freeholders or the Governor to fill a vacancy either for the unexpired term or temporarily, shall have all the qualifications required by statute to qualify for election to the office. If the previous incumbent had been elected to office as the nominee of a political party as defined in Title 19 of the Revised Statutes, the person so appointed shall be of the same political party as the preceding incumbent.