The code where I am (Ontario) states that no switch or receptacle is to be located closer than 39.4" from the outer edge of a shower. Basically out of reach. Any receptacles within 118" of a bath-tub, shower stall or sink must be GFI protected. Only the bathroom receptacles are specified to be either a GFI-type outlet, or a standard duplex receptacle supplied with a GFCI curcuit breaker. Based on this, if you need to put a GFI-protected SWITCH in, you have to use a GFCI breaker at the panel. I have never seen a GFI-switch before, maybe check the hardware store. The code here says nothing about switches being GFI protected, it only specifies where they are to be located (which would have a lot to do with safety). Hopefully that helps a little, though it's not really a yes or no answer, and the codes may vary (how much, I don't know).