Determining the age of a home’s wiring is something best left to a trained electrician—it’s not something a typical homeowner or home inspector can identify. Since most homes built between 1920 and 1960 used wiring that can dry rot and cause problems, it’s best to schedule an electrical inspection if you have an older home. Signs you have an out-of-date system include too few outlets, frayed wiring, damaged electrical plugs, or uncovered junction boxes.