Fortunately not mine!

A friend just told me "I have just replaced a single electric socket in
our lounge with a switched double. In order to stop the supply, I had to
switch off two trip switches at the same time." That didn't sound right,
or safe.

DIYWiki notes: at (http://wiki.diyfaq.org.uk/index.php/Ring_circuit):
"The ring circuit cable starts at the consumer unit (fusebox]), visits
each socket in turn, and then returns to the consumer unit. The 2 cable
ends at the CU are connected together in all modern rings, and supplied
by one fuse or MCB."

That confirms there should be one MCB, but I note the use of "...in all
modern rings...". Does that mean there might have been two fuses or MCBs
in early rings? I think his house was built around 1980.

--

Jeff