On 01/08/2019 21:00, alan_m wrote:
i) could the existing switch be removed and the wires joined in a
acceptable manner in the existing back box which will then be later
tiled over, perhaps with protective cover plate over the back box.?

[snip]

iii) could the switch be moved horizontally from the existing backbox by
channeling out the wall and running new wire from the is backbox
(connected to the existing wires)? And how near (horizontally) from the
hob could the switch be fitted?Â* There would be approx 45 cm between the
edge of the hob and the architrave for a door.

Bear in mind that the safe zones for cables feeding the switch are the
vertical and horizontal lines through it.

http://wiki.diyfaq.org.uk/index.php/...lectric_cables

Extending the cable sideways and tiling over the joint in the backbox
results in the original vertical drop no longer being in a safe zone and
there's a danger of someone assuming it's safe to drill into the wall there.

One solution would be to chase out the vertical cable and re-route it
along the top of the wall within 150mm of the ceiling and then down to
the new switch via a joint in a backbox at the top of the new vertical
section.

An alternative cheap and cheerful solution if you extend horizontally
from the existing backbox to be tiled over would be to fix a blanking
plate to the top of the wall wall as a marker vertically above the old
switch.