N.J. Stat. § 18A:54-27
There shall be for each county system of vocational schools a board of school estimate, which shall consist of two members of the board of education of the school, appointed by that board, two members of the board of chosen freeholders of the county in which the school is situate, appointed by that board, and the county supervisor of the county, in counties of the first class, and the director of the board of chosen freeholders, in other counties.
The appointments shall be made annually between January 1 and January 15. In case of a vacancy occurring in the board by reason of the resignation, death, or removal of any appointed member, the vacancy shall be filled immediately by the body which originally appointed the member, by appointing another of its members to fill the vacancy. The secretary of the board of education of the school shall be the secretary of the board of school estimate, but shall receive no compensation as such.
N.J.S. § 18A:54-27