Dual switches from single source

[rick carpenter]

For two separate switches from a single power source in a box out to one light per switch, I've seen an online diagram that puzzles me. Ordinarily for a single switch, the hot will be spliced to the switch, and the neutral and ground will pass through directly to the light. Dual switches shouldn't be that different, right?

In the diagram in question:
The hot is pigtailed to the switches then out to the lights - no problem
The neutral and ground are spliced & passed through to the lights - no problem
The ground is also pigtailed to the switches - necessary?
The ground is also pigtailed to earth - necessary?

Are the last two groundings necessary or would it "just not hurt" to do that? How do I ground to earth if I want to use a plastic 2 gang old work box? I couldn't save the original image so I re-drew it.

 

[exranger06]

All switches have a ground screw. You need to connect a ground wire to them by code. Back in the day, switches didn't have ground screws and you didn't connect a ground to them, but now you do. The part showing ground connected to Earth is kind of redundant as the ground wire connects to Earth back at the panel. I don't think the illustrator meant you literally connect a wire to Earth, that was just his way of labeling the wire as a ground.

 

[rick carpenter]

All switches have a ground screw. You need to connect a ground wire to them by code. Back in the day, switches didn't have ground screws and you didn't connect a ground to them, but now you do. The part showing ground connected to Earth is kind of redundant as the ground wire connects to Earth back at the panel. I don't think the illustrator meant you literally connect a wire to Earth, that was just his way of labeling the wire as a ground.

Ahhh, now I understand. Thanks!