Originally Posted by bdl99

It doesn't matter where you ground it, the point just needs to be a ground. The point you show should be a good ground, but you can always check with a meter and check continuity between that point and a know ground point. The connection with your added call-out should be the connection going to ground shown in your 3rd picture, so from the switch to ground.

Can you send a picture of how you have wired the back of the switch? I think that is more likely to be the issue.