A couple of other points about permits and your property:
In the case of the shed wiring burning down the house, remember that your home insurance company will check to see if the cause of the fire was due to unapproved improvements, which are known as conscience of negligence. In this case, if the wiring to the shed was never approved, they (your insurance) would not pay for the rebuilding of your house.
In addition, Real Estate agents today often check to see if everything on the property had proper permits, because legally anything not approved has no value. This means, if you are asking $25,000 more for a home because of "extras" that should have needed permits, but did not have them, you really canít claim them as extra value. Furthermore, if something happens with the new owners, and it gets traced to negligence on your behalf, plan to spend some time in court. Your agent, too, could be liable.
For the most part, these rules are for our own good and protection. People should follow them for their own safety, and not constantly evaluate ways to avoid them, and risks of getting caught.