-=D@n=- wrote:

much like-for-like. The problem is, I think the wire goes from outside into
the wall, and somehow into the void between the ceiling of a downstairs
bathroom and under the floor of an upstairs room. It will be a pain to
replace the wire.

Remember that if you do decide to replace the wire, then there is no
requirement that the new wire follows the same route as the old one. If
there is a much simpler routing for it then you are free to use it. In
this case you ought to find where the feed to the other wire is and
disconnect it (you can leave the now disconnected wire itself in place
if you want). The feed will typically be at the CU itself, or more
likely at the nearest accessible light fitting on the same circuit.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/