Regulation for rewring back box?

The most useful thing you can do for the next electrician in is leave an envelope of photos and or wiring drawings near the consumer unit. This almost never happens, but knowing where the joints are and how things are wired really saves a lot of time. 

Do not worry about the notification part. 

Putting the full weight of the regs to one side for a minute, the level of testing that is really required for a safe light switch swap you can probably do with careful use of a cheap multi-meter or even a battery and buzzer set, as with a bit of thought it can all be done ‘dead’ - i.e. with the power off.  ‘proper’ electricians test sets have fused tips on the probes,  and can measure very high and very low resistances very accurately, and have a price that reflects this. 

But this is a light switch swap,  not the rewire of a hospital… You may however still need a long ‘wander lead’ and a tame accomplice.

It is useful to either write on the cable (sharpie pens) or use coloured tapes to be sure which wire is which - putting the switch straight across the supply instead of in series with the lamps is a dramatic and confidence reducing  event.

spare cables should be insulated and folded back out the way rather than cut short unless there is a good reason - you may need to revert at some point. (it is good practice to earth unused cables, but not essential to safe operation)

Mike.

The most useful thing you can do for the next electrician in is leave an envelope of photos and or wiring drawings near the consumer unit. This almost never happens, but knowing where the joints are and how things are wired really saves a lot of time. 

Do not worry about the notification part. 

Putting the full weight of the regs to one side for a minute, the level of testing that is really required for a safe light switch swap you can probably do with careful use of a cheap multi-meter or even a battery and buzzer set, as with a bit of thought it can all be done ‘dead’ - i.e. with the power off.  ‘proper’ electricians test sets have fused tips on the probes,  and can measure very high and very low resistances very accurately, and have a price that reflects this. 

But this is a light switch swap,  not the rewire of a hospital… You may however still need a long ‘wander lead’ and a tame accomplice.

It is useful to either write on the cable (sharpie pens) or use coloured tapes to be sure which wire is which - putting the switch straight across the supply instead of in series with the lamps is a dramatic and confidence reducing  event.

spare cables should be insulated and folded back out the way rather than cut short unless there is a good reason - you may need to revert at some point. (it is good practice to earth unused cables, but not essential to safe operation)

Mike.