Both times I tried to send you a message and had errors or I pushed send by mistake.. Here is my situation again.  I want to install a USB charger that has outlets on it. On theis unit there are 3 screws. Theres a gold screw, a silver screw and a green screw.

I know that if i was installing this with its own dedicated wire, I would simply connect the hot to the gold, neutral to the silver and ground to the green.

But…

 

Problem 1

I need to feed power to the adjacent switch on one wall. How do I connect to the switch that has 3 screws?

 

Problem 2 (Totally different area)

On the other wall I am simply replacing the existing power outlets with a usb charger like the first one. But the outlet that is there has 4 screws and a ground. The two left screws each have a black wire connected. And the 2 screws on the left have a white wire connected to each of  them.

There are only 3 screws on the usb charger