I feel so strongly about the sanctity of our election system I signed up months ago to be poll worker/inspector. I went through the training, passed the tests and will be working tomorrow.
In my country there are 3 ways for registered voters to vote: absentee ballot, early voting and in person, election day voting.
If someone mails an absentee ballot and then goes to the polling booth on election day either by mistake or attempted fraud, the in-person vote will automatically cancel the mail in vote.
And the attempt/error will be flagged and recorded.

We will see if the rhetoric spewed by a candidate campaigning in North Carolina will encourage people to try, even if it is illegal – and pointless.