Mail-in ballots posted on Facebook Marketplace near Goleta

SANTA BARBARA COUNTY, Calif. - Multiple Santa Barbara County mail-in ballots have been posted to Facebook Marketplace as free items in the Goleta area, not long after they were initially sent out by the Santa Barbara County Department of Elections two weeks ago.

One woman who posted says she is trying to locate the rightful owners of two ballots that were sent to the wrong address. Another post includes photos of two more mail-in ballots, but with no description.

The Santa Barbara County Department of Elections says if voters receive someone else's ballot in the mail, they should write "No longer at address, return to sender" on it and put it back in the mail. This alerts the Elections Office to deactivate the incorrect voter registration.

President Trump has repeatedly expressed concerns over widespread voter fraud through mail-in voting. FBI Director Christopher Wray rejected that theory last month.

"We have not seen, historically, any kind of coordinated national voter fraud effort in a major election, whether it's by mail or otherwise," he said.

Controversy is brewing in other parts of California, as the state's GOP party acknowledged owning unofficial ballot drop boxes. They had been reported in Los Angeles, Orange and Fresno Counties.

One box in front of a church in Castaic was incorrectly labeled "official."

Secretary of State Alex Padilla says operating any unofficial ballot drop boxes is against state law.