Starting in 2016, nearly all Wisconsin voters must show an acceptable Voter Photo ID in order to cast a vote (see below for some exceptions) 

Photo ID Residency
League Pamphlet, Making It Clear is a tool for community members helping citizens navigate requirements for registering and voting in Wisconsin. It clarifies many of the ambiguities surrounding proof of residence and voter photo IDs.
Making It Clear
The League of Women Voters has prepared a helpful explanation on the proof of residency rules when registering to vote.
Proof of Residency Guide
The League of Women Voters has prepared a poster to help voters understand whether they are ready to vote. It is available in two languages: English poster or Spanish poster The DMV also offers guidance on what documents will be accepted to prove Wisconsin residency when obtaining a voter photo ID.
Proof of Wisconsin Residency
The Government Accountability Board explains Voter Photo IDs here: Acceptable Photo IDs and a poster

Acceptable Photo IDs

You can call the Government Accountability Board to ask questions at: 1-866-VOTE-WIS
Proof of Residency can often be looked up online. Here is a handy list of websites:
Proof of Residency
Wisconsin state law requires voters to provide a voter photo ID to receive a ballot on election day or to vote absentee. The Wisconsin Government Accountability Board (GAB) provides extensive information on this topic on its website, including descriptions of documents that are acceptable as voter photo IDs. 
Acceptable Photo IDs for Voting in Wisconsin
Registering UW students presents some unique challenges. Here are Tips – Registering to Vote for UW-Madison Students
The Government Accountability Board explains 
Military and Overseas Voters

For voters who do not have an acceptable voter photo ID, the Department of Motor Vehicles (DMV) website provides detailed information about how to obtain a free voter photo ID for voting purposes. 
Obtaining an ID Card 

Questions? Call the DMV Voter ID Hotline at 608-266-1069
 
Acceptable Documents for a Wis driver license or ID card application.
English language   Spanish language