Walz said "ELECTION misinformation." He was talking about sending out false info such as, "Your voting location has been moved from PS 10 on First St. to PS 30 on Travis Road." or text message campaigns or robocall campaigns with similar types of misinformation: "Mail in ballots are no longer being accepted this year. If you received a mail-in ballot, tear it up and make arrangements to vote in person (at a fake voting site)." Such misinformation is intended to deprive the carefully targeted voters of their vote.  
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I think Walz was also referring to post-election misinformation such as "I saw an election worker dump 1000s of ballots for my preferred candidate into a dumpster behind the supermarket." or "Italian satellites were used to change the vote count in the places where my preferred candidate lost. I have proof!"
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If people DO have proof that the voting site HAS been moved or that ballots HAVE been changed then they will present it and show that it was NOT misinformation and not be charged.  
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There have already been some cases prosecuted for those sorts of activities but I don't know which laws were applied. Probably existing "election interference" or related laws and NOT any sort of "criminal misinformation" statute.  
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I don't think Walz was talking about candidates lying to the press or in their ads with campaign misinformation such as, "Obama was born in Kenya!" or "Kamabla drinks the blood of babies!" or "I was with Willie Brown in a helicopter that nearly crashed. He told me things about Kamabla." or "Joan Rivers told me she voted for me." (Must have been from her grave since she died in 2014.)