A Photo ID is needed to vote on Election Day and if you're voting via Absentee Ballot.
Print out a flyer - BRING IT to the BALLOT - describing the process and answering a few questions you may have.
The following are some acceptable photo id's and each is a link to a more in-depth review of that type of ID:
Wisconsin receipt for your Driver's License or ID Card
SOME Student ID Cards
CONCERNED that you don't have acceptable ID. The DMV offers a petition process.