Using UK toggle light switch in the US?
You need to use switches rated for at least 15 amps.  Most UK switches are rated at 10 amps. You could solve that problem by wiring the light through a relay such as a RiB or Aube type low-voltage relay. 

Mechanically mounting it in the walls would be easy enough. The trick is don't try to mix-and-match. Use all-UK stuff up until an obvious point of divergence.   So for instance, put the UK switch with a UK cover plate in a UK junction box with UK cable clamps.  The place to transition to US style stuff is at the cable or conduit.  You might have to punch a 1/2"US knockout in the side of the UK box, if you were fitting conduit.  Otherwise UK twin-and-earth clamps will probably work on Romex. 

No ring circuits, though.