N.J. Stat. Ann. § 40:80-1

The legal voters of any municipality may adopt this subtitle at a special election to be held in such municipality, to be called by the municipal clerk upon request or petition in writing of the legal voters of the municipality not less in number than fifteen per centum (15%) of the number of persons who voted at the last preceding general election held for the purpose of electing all of the members of the general assembly as shown by the official canvass. At this election no other proposition shall be voted upon.