David! I have a slightly different suggestion. Anyone who wishes to do any work except replacing accessories is required to have a limited license. A theory exam and a practical test should be enough. This license is limited to unpaid residential work. For paid work or work in commercial environments it will only be good for minor work on existing circuits. (Lot's of installers just need some power for their system, not a whole new circuit.)
Rest of work is reserved for real Electricans.
