Here's an interesting story out of Iowa that you likely have not heard about. In the 2nd Congressional District in Iowa, the Republican candidate was certified the winner by a six vote margin. However, there were 22 votes that were not counted - and no one, apparently not even the Republican candidate - is claiming that they are illegal votes. The Republicans admit the 22 votes were "erroneously not counted."
There is an argument over the process to contest the election, with the Republicans claiming that the Democratic candidate has not exhausted state remedies before contesting the election with the House of Representatives and therefore the petition must be dismissed and the certified result upheld. The GOP argument that state remedies must be exhausted first is contested by the Democrats because (1) the federal law does not require it; (2) state courts would likely find the matter moot; (3) precedent demonstrates no need for state exhaustion, and; (4) absent direct petition to the House there would be no remedy for 22 uncounted votes with no explanation.
The Democratic candidate won on 18 of the 22 uncounted ballots. The Republican has been provisionally seated in the House, but if the petition is successful the Democratic candidate will be declared the winner of the election.