A locked ballot box in Humboldt County turned up a surprise this week — nearly 600 ballots from the most recent special election that were never counted. Election officials say the sealed ballots were tied to California’s Prop 50 vote and were discovered Monday night. The measure still passed easily, so the missing ballots would not have changed the final result. Even so, Humboldt County’s top elections official says the mistake should never have happened and the county is now trying to process the ballots.