-- Volunteer Income Tax Assistance (VITA) program:
        Free tax help for low-income individuals, individuals with disabilities, non-English speakers, and military personnel.
       Cooperative effort of the IRS and individual states.
-- Taxpayer Counseling for the Elderly (TCE) program:
       Free tax help to individuals who are age 60 or older.
       Cooperative effort of the IRS, Wisconsin and the AARP.

Note: each program has different eligibility criteria and other requirements; please review carefully:

Information from Wisconsin Department of Revenue on the VITA and TCE free tax assistance programs.
  

Additional information from the IRS on the VITA and TCE free tax assistance programs.
   -- IRS VITA Locator Tool

Free individualized tax preparation for low-to moderate-income taxpayers - especially those 50 and older.
   -- Tax-Aide Site Locator