An Essex County campaign worker was convicted today of absentee ballot fraud that occurred during the 2007 election of state Sen. Teresa Ruiz. John Fernandez, 61, of Belleville, was found guilty of election fraud following a two-week trial.  The jury found Fernandez guilty of charges of conspiracy (2nd degree), election fraud (2nd degree), absentee ballot fraud (3rd degree), tampering with public records or information (3rd degree), and forgery (4th degree). The Mercer County jury found that  Fernandez, who works for the Essex County Department of Economic Development, fraudulently tampered with documentation for absentee ballots in Ruiz’s Nov. 6, 2007 general election, submitting ballots on behalf of voters who never received the ballots or had an opportunity to cast their votes.