This homeowner was experiencing inconsistent home temperatures. In the winter it would be very cold and expensive to heat, and in the summer it would be extra hot and expensive to cool. This problem is one we see often.
Before insulating, we went ahead and air-sealed all of the can-lights, bathroom fans, and cracks/gaps. We then went in with blown cellulose insulation with an R-value of 60. Previously, the homeowner had blown fiberglass insulation (we do not recommend for many reasons) in their attic with an R-value of 30! Wisconsin is in climate zone 5, and according to the U.S. Department of Energy, the target R-value for attic insulation in climate zone 5 should be 40-60! No wonder they were experiencing inconsistent temperatures.