Also, the State of WI has a great website showing where higher amounts of radon persist on a map. It also provides great facts about radon. did you know while it can be deadly over periods of time, that is alo usaully very correctable? Radon mitigation systems cost anywhere from $900-1300 (usually closer to $1000.) to install with very high effectiveness. Good luck.
If it's "peace of mind" you're looking for, you can buy radon testing kits, and do the occasional test now and then after you've taken possession. If you do find Radon, remediation isn't expensive... depending on the property, it could be $500 - $1,500 to repair the problem with a semi-permanent solution.
And you can always do one after the closing.
Coldwell Banker Residential Brokerage