The main one is for heating control. 5 core.
or look at the voltage spec of towbar / traffic light cables. 7 Core These should be available in short lengths
Well I can confirm these BG euro sockets can accept both euro 2A and UK shaver plugs nicely.
So great for charging your tooth brush and shaver which can come with either plug.
No heat output. No buzzing.
And you can get 2 dual outlet ones on eBay at present for less than £5
Chrome &...
Against regulators but I like these.
Can then charge your euro plugged devices
But I like your USB C idea/device which is compliant.
https://ebay.us/m/JrPYTX
You can also get doubles, which the back box that is compatable with the standard UK shaver face plate
Or
https://ebay.us/m/bN21n0
car reversing lights aren't what they were.
Many have down graded 21W bulbs to 16W bulbs and with small windows in the lens.
They do sell plug is replacement capless bulbs in the 21W version, which maybe an easy option.
As for the house, well you could fit one of those fashionable up and down...
didn't know that rule.
But that's not an intermediate switch.
probably a wiring error at the switch.
Start by seeing what colours are present at the fan if easy.