If your home has an old Knob and Tube wiring system, you should consider spending the money to have a professional electrician update your home to a modern wiring system. The cost of this job will naturally vary depending on the electrician, size of the home, and many other factors. According to Angie’s List
, though, the average cost of rewiring a 1,500 to 3,000 square foot home will be in the range of $8,000 to $15,000.