This is a real worry for a lot of people; nursing home care is increasingly expensive, and a significant percentage of people do need long-term or nursing home care at some point in their lives. It may ease your mind to know that if you are still living independently, as the "community spouse", you are entitled to keep a certain amount of assets and income. However, there are some additional things you can do to legally protect more of your assets and income and to help your spouse qualify for Medical Assistance (as Medicaid is called in Wisconsin), sooner. (Medicare does not pay for nursing home care except in very limited circumstances.)
There is a right way and a wrong way to go about this, and the government may delay or withhold benefits from your spouse if it believes you have unlawfully transferred assets in order to qualify for benefits. Whether you are simply planning for future possibilities, or your spouse is already in a nursing home, this type of planning is something you definitely need an experienced Wisconsin elder law attorney's help with.