Aggregating some information in this comment based on what I’ve read throughout the internet.

1. Authorities have identified the vehicle of the one in Oregon (and likely Washington) and probably know who’s behind it at this point. AP News
2. Authorities have arrested the person responsible for the ballot fires in Phoenix ABC Phoenix
3. There was a conversation on Truth Social from a user named Elwoodblues50 that suggested doing just this. I have no idea how coordinated it was, but it definitely sounds like something that has been going around right wing circles for a bit. sorry Reddit link
4. These ballot boxes have measures to protect the ballots in the case of fire. One of the ballot boxes had up to 100 ballots destroyed, the others were in the single digits.
5. Oregon and Washington both have websites that allow you to check the status of your ballot. If you know anyone in who may have been impacted by this, have them check the websites and request a new ballot if theirs wasn’t accepted. Oregon. Washington

Bob Newhart, everybody!

Sigh. The ol “We investigated ourselves and found no wrongdoing.”