There have been reports like this in other areas of the country too:

SAMMAMISH, Wash. – Sammamish Police are investigating potential mail theft after two garbage bags of mail, which included ballots, were found on the side of the road and several unopened ballots were found in incorrect mail boxes.

Source: Sammamish Police: Garbage bags of mail found on side of road included unopened ballots | KATU

Coldstreams Skeptic