Wanted to post this some time ago, but only remembered when I gave it a quick wipe down this morning.
the light switch to the workshop gets pretty grimy after a while and from continuous cleaning and sometimes missing the actual switch and touching the wall the area around the switch also gets grimy.
A left over wall tile fitted under the switch face plate. I cut the hole with an angle grinder, cemented it to the wall and then some extra long screws to secure the switch to the switch box.
Now it is very easy to clean and no problem to clean around the switch.