evidence: For an absentee ballot to count in Wisconsin, a voter and a witness must sign the ballot envelope and include the address of the witness. Those safeguards — put in place to eliminate mail-in ballot fraud — in fact contributed to the rejection of 13,834 ballots, according to APM Reports' analysis. [...] Nine states require a witness signature to submit an absentee ballot. Another three states require at least two witnesses or a notary agent, according to the nonpartisan Brookings Institution. [...] For example, a lower court waived the witness signature requirement on absentee ballots, but the ruling was later reversed. The courts also shifted the deadlines for returning absentee ballots.