[Normy]

Forget about the green wire.

Your switch isn't grounded. In the future, when you go to sell the house, an inspector will come in and test it; it will go in the report. If you aren't worried about this yourself, then don't worry about it. On the side I work for a small company in Fort Lauderdale, and we have 33 rental units and 4 rental houses. I deal with this all the time, and I cannot count how many times I have installed lights and fans in ceilings where the ground doesn't exist.

Just install your switch, forget about the green wire.

N!