Who is an “Overseas Voter”?
You are an overseas voter if you are a U.S. citizen who last resided in Wisconsin, or your parent last resided in Wisconsin, before moving to a foreign country, and you have no intent to return to your prior municipality in Wisconsin. These voters are often called “permanent” overseas voters.
Overseas voters may only vote for federal offices.
Voters who are temporarily overseas on Election Day (such as students studying abroad, or people living overseas temporarily for work), but still reside in Wisconsin and intend to return to the United States are considered temporary overseas voters. Temporary overseas voters must register and vote like any other elector, but are NOT considered an overseas voter in Wisconsin.
Find more information at the above link.