The Fond du Lac city clerk is urging residents who receive a voter registration postcard in the mail to take action to ensure their registration address is up to date. Nearly 100,000 Wisconsin voters identified as potentially having moved since the fall of 2019 are being mailed postcards from the Elections Commission. Fond du Lac city clerk Maggie Hefter says the postcard is very specific. In the past Hefter says most of the postcards come back to her office marked undeliverable. The mailing is the first since the Wisconsin Supreme Court ruled in April that the commission should not deactivate the registration of anyone identified as potentially having moved. Local election clerks can remove voters from the rolls, but they must first give them notice in writing 30 days ahead of taking that action.