If you can read and follow instructions this post will help you:
https://somebitchtoldme.com/maidengate-2-electric-boogaloo-how-california-is-setting-itself-up-for-a-vote-by-mail-disaster/
You may have to go to the voter registration sites in several states, but you might be able to determine if ballots were sent to an old address and filled out "for" you.