N.J. Stat. Ann. § 40A:9-108

No person shall hold any other civil office during the time he holds and exercises the office of sheriff and by acceptance of the latter office his former office shall be deemed vacated, provided, however, that the governing body of any county may, by ordinance or resolution, as appropriate, provide that any person holding and exercising the office of sheriff may simultaneously hold and exercise the office of county emergency management coordinator but shall not receive any compensation or any other benefits otherwise attached to the office of county emergency management coordinator during such time as such person shall hold both such offices.