I recently snagged a new house wire, fully signed off already by a newly qualified electrician who was NIC Domestic Installer. He had been trading for 4 months or so. The new owners called me in as I had rewired their parents home some years ago. They were having numerous problems and the original sparks was AWOL. Here is a list of what I had to do.
Re-do the 3 way lighting to hall stairs and landing as the intermediate switch was incorrectly wired.
Replace badly wired recessed downlights as cables were scorched
Re-site the above as 3 were up against beams.
Rewire fan isolators as fans were on permanently
Fix compression faults in cooker and shower boxes as 6mm and 10mm cable squeezed into 25mm boxes.
Remove DG socket from above sink
Fit link cables between mains fire alarms. ( They were non radio linked ,individually powered from lighting roses.
Conductor identification throughout house ( there was none)
Heat alarm to kitchen (smoke fitted)
Extend smoke alarm system to intregal garage ( nothing there) to fit heat alarm
Mark up CU
Reconfigure CU ( was a mess)
Fit earth to water
Rewire central heating system ( S plan +) CH only working when HW enabled
Fit waterproof socket outside ( Metal DG socket fitted there)
Find and fix earth pulled from ring in Lounge
There were a few other things but you get the picture I guess
Qualifications mean nothing, experience is everything