Wisconsin Elections Commission Chair Ann Jacobs took to social media Wednesday with an unusual warning for voters in her state that bets placed on a prediction market could get their ballots thrown out.Under an obscure state statute, Wisconsin residents are banned from voting in an election in which they have become "interested, directly or indirectly, in any bet or wager depending upon the result of the election. Anyone can file a complaint to trigger a challenge.Even so, approximately $18,000 has been wagered on Wisconsin races, according to a Washington Post analysis of Polymarket data. “I know it’s all the rage to bet on everything, but you cannot bet on an election in Wisconsin,” Elections Commission Chair Ann Jacobs said on X . “If you do, your ballot can be challenged & thrown out. … So go vote and save your $ for playing Euchre with your uncle!”Prediction markets are regulated at the federal level. The Commodity Futures Trading Commission officially designated them as financial instruments under federal jurisdiction earlier this year, after courts ruled that election contracts don't constitute illegal gambling under federal law. Kalshi, the largest U.S. prediction market, has operated as a federally approved exchange since 2020.Experts told the Washington Post that actual prosecutions under the statute would be politically toxic and nearly impossible to pursue. "If you go and find John Q. Citizen betting $50 on an election, and you do something to this person, you’re going to look not so good. It's not worth the time," said Koleman Strumpf, a political economy professor at Wake Forest who specializes in prediction markets.