In case it's not clear, I don't actually have any reason to believe that any election I'm aware of has has it's outcome fabricated. I was mostly intrigued by the parent commenter's assertion that it was impossible for the people in charge to just lie about an election since clearly it's possibly for them to at least try. I realized I don't actually know who has the power to hold them accountable, and I was curious if there was a definitive answer for this sort of thing (and although it likely varies by location given how decentralized election regulations are in the US, it seemed like the parent commenter had some first-hand knowledge of how their local elections work and might already know the answer).

Continuing the hypothetical you suggest, what would an individual actually be able to achieve if they did somehow get the evidence they were looking for that the vote count was fabricated? Is there some sort of civil procedure for contesting the vote tally? Would it require a lawsuit against the person or group of people who lied about the totals? Is there some sort of hearing where people can make a case that whoever is supposed to certify the count (e.g. the legislature) can argue against it? Or would it just be a matter of fighting in the court of public opinion to mount enough pressure to get the lying party to cave?