A voter may write-in the name of a candidate on the ballot in New Jersey.
Voters must write in the name and register the vote by making a mark in the ballot in the appropriate space selecting the write-in option. Otherwise, the vote will likely not be counted. Please see the sample ballot.
In NJ, both "Bernie Sanders" and "Bernard Sanders" are acceptable and will be cumulatively totaled.
You need not specify a Vice Presidential candidate in order for votes for Bernie to be counted. Should Bernie win in New Jersey, he will choose his VP and electors post election.
Law prohibits voters from showing their ballot to others. A pending legislative measure would allow voters to take photos of their own ballots while in the voting booth and share it on social media. Please take a picture for your own records, but do not share or disseminate publicly.
(N.J. Stat. Ann. §§19:1-1, 19:5-1, 19:13-2, 19:13-1, 19:13-3,19:13-4, 19:13-5, 19:13-9, 19:13-15, 19:53A5)
A write-in candidate is not required to submit any forms with any filing authority. The ballot will allow as many blank lines for write-in candidates as there are persons to be elected.BallotPedia: Write-in candidates, New Jersey