Probably not. A Google search shows that Wisconsin's general fraud statute of limitations is six years. However, it is sometimes the case that if a potential defendant has been out of the state of country for some period of time, that can affect the limitations period. If this is more than a casual question and a substantial sum is at issue, you should consult with a Wisconsin lawyer.
The general statute of limitations for charging an offense is six years for a felony offense and three years for a misdemeanor. A period of time outside the state or after issuance of a warrant is not counted towards the statute of limitations. So, the answer is it depends. You should contact an attorney to discuss the details of the situation confidentially if you are truly concerned about this.