When I first went self employed in 1988, I turned my hand to just about anything. Over a period of about 12 years, I did all sorts of work.
In one house, I replaced two floors from the foundations up.
One floor in the hallway 20’x 8’, the other in a room 24’x 12’.
Had to support the staircase with breeze blocks and car scissor jacks, rebuild all the brick pillars, replace all the joists and laid a floor from reclaimed planks taken from the side of a barn near where I was living
I replaced the rewire-able fuse box with a split load CU and installed some wall lights in the big room.
Demolished some out buildings and rebuilt a small lean-to.
Got a mate in to plaster the big room and another to paint it.
I did creosote the lean-to.
Another house, I would go round every so often to trim bushes and trees, fix the kitchen lights, replace the odd light fitting and even re-install a double socket that had been installed upside down (live conductor was too short to reach the terminal, the right way up).
Other work involved me going to a mate’s car garage and doing the odd bit of welding for him, replacing his fuse box and also replacing the fuse box in the cafe round the corner.
Still get the odd bit of electrical work from that cafe owner even now.
I also got work for Pimlico Council re-wiring flats in a Mansion block.
I got work for Epping Forest Council toshing out 3 maisonettes on the Limes Farm estate. Had to reconnect an RFC in one, as a link had been left out when a wall had been replaced.
During those 12 years, I did no advertising, it was all word of mouth. I doubt anyone would have described me as an Electrician, most likely as a welder or car mechanic, or even gardener.
Thing is, I qualified as an Electrician in 1983. C&G 2369 parts 1 & 2.
The point of all this, is for all those banging on about employing a painter to do electrical work.
The OP employed the painter because he was recommended.
I hear a lot of advice on here for people who want electrical work done. Most of it is to choose someone recommended by friends or neighbours.
Don’t get me wrong, the painter did a poor job.
No worse though than work I’ve seen done by qualified and registered electricians.