In uk.d-i-y, Peter wrote:
The light switch in my downstairs toilet is just a normal rocker type.
ISTM this is somewhat dangerous due to the proximity of basin & WC, so
I'm looking for a safer solution.

I think you're being over-cautious. It's not a *bath* or a shower in
there, just a bog and basin. People using it aren't likely to present
a lower-resistance path to earth than usual, or even have particularly
wet hands when operating that switch, unless you get up to more interesting
stuff in the downstairs loo than most of us ;-)

If you want to fuss, there are cheapie "outdoor" switches available from
Screwfix and the sheds which have a transparent cover over the switching
element, and don't cost an arm and a leg. (Unlike the MK outdoor switches,
which are more seriously rainproof but weigh in at 15 quid or so!). Or
for a touch of Coronation Street sophistication, along with the three
ducks on the wall, you could put a touch-operated dimmer in; or just a
large-plate rocker switch (some designs have effectively the whole of
the plate area as the rocker), so that the already remote chance of
drips-from-fingers causing a tingle is further reduced.

Oh, and do make sure the cable to the switch has an earth, and measure
- if poss - that it really is connected to the house earth; and that the
back box (if you have a metal one) is connected to said earth. That's a
more significant - but still small - risk than the one you seem to be
concerned about.

HTH - Stefek