N.J. Stat. Ann. § 40:71-1

The legal voters of any municipality not governed by chapters 70 to 76 of this title (s. 40:70-1 et seq.) may adopt said chapters at an election held in such municipality, to be called by the municipal clerk upon request or petition in writing of twenty per cent of the persons qualified to vote at the last general election as shown by the registry of qualified voters used at such election.