Sometime around the I think late 50's / early 60's BICC produced the Octpus wiring system which was used for wiring flats I believe it had a central box and all the cables were terminated into it this was laid out on the shuttering and the cables laid out to there various positions before the concrete was poured. A friend of my mum worked at the BICC factory in Prescot terminating the ends on piece work and was paid something like 3d per end it doesn't sound a lot but they could terminate upto 20 ends per hour. I remember seeing the film at college back in the 70's and it was amazing how they did itHave never know MICC to be used domestically except as a sub main up a tenement building in Edinburgh.
Around Prescot you quite often find the odd older house wired in MICC usually the owner or past owner worked at the MICC part of the factory or were a relative of someone who worked there