Schwarzenegger, the state's last Republican governor, was asked during a CNN interview to respond to the California Republican Party placing unauthorized ballot boxes in at least three counties.
Republicans have defended the move as no different than Democrats going door-to-door to collect ballots from sympathetic voters, but state officials have ordered the party to remove the boxes because, they said, only counties are allowed to establish them.
He and other state leaders say the boxes are unsecured and could confuse voters who mistake them for official ballot collection boxes as they return their mail ballots.
Republicans, however, say they are on firm legal ground because California law allows third parties to collect ballots and submit them on behalf of voters.
In deep-blue California, the party has since lost even more ground to Democrats and until recently trailed the number of independent voters in the state.
Delivered monthly, California CEO Report gives you a high-level outlook on policy issues driving the agenda in the Golden State