Secretary of State Kathy Boockvar said Pennsylvania voters have already returned more than half of the main-in ballots that were distributed.
She said 1.4 million voters have returned their ballots, so far, for the November 3 election.
Earlier this month, the Supreme court ruled that Pennsylvania can count mail-in ballots received up to three days after the election.
Governor Tom Wolf supported the decision on the KDKA radio Morning Show. "When it comes to elections laws, the state ought to be in charge of its own destiny and the state supreme court made a ruling and it stands," he said.
On October 14, the Allegheny County Elections Division made the announcement that more than 28,000 voters received the wrong mail-in ballot due to a printing error.
New ballots were mailed out and should have been received by voters this week.
The Elections Office expanded hours through Election Day.