No Stupid Questions

The exact specifics vary based on the state, but it's roughly the same in each of them.
You track the voter, ballot, collection and counting.

Voter A issued ballot 3. Ballot 3 collected Ballot 3 counted.

The counting phase involves removing the tracking number from the ballot before removing a cover that keeps the vote private.

You can't slip an extra ballot into the box because then the totals don't add up, and you know where in the process the discrepancy occurred.
Making sure there are multiple eyes on issuing and counting means it's hard to create or count a fake ballot.
When not observed by multiple people, the containers are locked with multiple locks with keys held by different people.

It's why most voter fraud is a voter going to multiple valid voting locations to vote multiple times. Once the tabulations begin, you see you counted the number collected, collected the number issued, and that you issued one ballot to each voter except one, who got three.

How would a dishonest person add extra? Here in Australia you go in, get signed off on a book, and they give you a piece of paper for your voting preferences. You don’t get unlimited papers to vote multiple times.

For early voting they mail us out a sheet and reply envelope, and we mail it back. Or you can go into a few of the early voting centres dotted around.

There’s also phone voting and come to you voting for those who require such services.

Early voting is consolidated into fewer locations than the voting precincts on Election Day.

the early voting sites are exactly like the election day sites there are just fewer of them as you do not need one for every district just like my suburb has several voting locations based on the district your in but just one early voting location in city hall. You can use any early voting location though so I could go downtown into the city where there is one or one from some other burb as long as its in the state.

There are two types of early voting.

For in person voting, the local election board opens up fewer voting locations before the election. If approved, you can vote there and then instead. A lot of states eliminated any requirements to early voting after Covid.

For mail-in voting, the ballot gets mailed through USPS to voters. The ballots are usually supplied with an envelope with a way to verify identity, usually with signature. From there, the voter has the option to either mail the ballot back or directly deliver it to specific drop boxes.

In my state (Colorado) early voting works exactly like regular voting, just, you know, earlier. Registered voters get their ballots automatically sent to them in the mail. You can return your ballot by mail, drop it off at an official drop box, drop it off at a voting location, or you can show up at one of the early voting locations in your county and vote in person the traditional way if you prefer that. Right now in my county there are six locations where you can do in-person early voting. There will be orders of magnitude more in-person voting locations open on the day of the election, but I think most people choose return their ballots by mail or drop box.

Every voting/counting location is staffed with a bipartisan team of election judges, and election observers. I believe the locations are run by paid county officials, but largely staffed by volunteers who have completed a training program. I've never heard of there being a shortage of volunteers

The voting drop boxes are big reinforced steel boxes which are securely anchored into concrete. You would need some seriously heavy duty cutting tools to get one open without the key. They are placed in front of city offices like City Hall, the Department of Motor Vehicles, or the city library. They're usually in open high traffic areas, and are under 24/7 video surveillance. I believe they're also emptied multiple times per day. I wouldn't say they're impossible to tamper with, but it would be extremely difficult to do so and get away with it. To my knowledge, so far nobody has tried. I'm not actually sure what it would really accomplish. I guess you could destroy ballots, but stuffing one with counterfeit ballots would probably be caught almost immediately.

There's a pretty robust system in place to track who has cast a ballot, how, when, and where. If multiple ballots show up in the name of the same voter, that gets automatically flagged and triggers a fraud investigation. Also there's signature verification system. Every ballot that's returned by mail or drop box must be returned in its security envelope, which has the name of the voter and several unique QR and bar codes containing information tying that envelope to that specific voter. This envelope must be signed by the voter for the ballot to be counted. If the signature on the security envelope doesn't match the signature on file, the ballot gets flagged for investigation, and doesn't get counted until the voter can be contacted to verify it was them casting the ballot and not someone pretending to be them. Voter fraud is really pretty rare here, but it's taken very seriously, and gets seriously investigated. When it does happen it's usually someone trying to cast the ballot of a deceased spouse, or family member, and even that usually gets caught.

There are a lot of safeguards and redundancies in place here that make getting away with voter fraud extremely difficult, but lot of the reason why our system works as well as it does is that people genuinely care about their votes being fairly counted and so are willing to staff and fund the offices who investigate voting irregularities. Our voting system is considered kind of the gold standard for the United States, and I'm lucky to live in a place that has that. Voting systems in other parts of the US are unfortunately not run with the same vigilance or sense of equity.