Seriously funny and good.
All you are looking to do is replace a wall switch with a dimmer type, would that be correct? I don't see where "ground fault" figures into this. Basic dimmer for incandescent light right? Not all dimmer switches require a ground. All you would need is a two wire dimmer, hot in and lamp on the output side.
Yes, your switch as is, is a mess but I have seen worse. One side of the switch should be Hot (always) and the other side the switched output. With Canada and US Mains power the worst case is you get a shock and if the mains is off at the breaker you are not likely to get a shock. This assumes you are in good health and not a cardiac patient.