UK How to repair switch with no circuit breaker?

[davesparks]

The first picture is the overall setup. The second is a close up of the communal meter (on the left in the picture). Thanks.View attachment 58941

The small consumer unit to the left of consumer unit A will be feeding the communal circuits.

When was the last time that mess was inspected and tested by an electrician?

 

[Vortigern]

See #4, there is no LL

That does not show there is not a LL. It shows that some people have a leasehold on a flat and the lease is to the superior LL. True they may have exercised their right to enfranchise and purchase the freehold however they would have had to form in effect a management company with LL as a legal fiction even if it is themselves. Unless of course they have a not very often used flying freehold.