It was based on this guys work: http://www.echotwek.com/wp/2014/03/20/arduino-controlled-light-switch-v2
I had a Leviton Decora switch P/N 5601 from Home Depot lying around and I was going to try this mod, when I popped the rocker off with a flat blade screwdriver I noticed there were rivet holes drilled right through from behind the rocker all the way out the back cover and grounded.
I took 2 pieces of DuPont connector wire I had for my Arudino projects and hot glued one to the top half and one to the bottom half of the back side of the rocker plate. I did not cut, or modify the switch in any way other than putting the wire through and adding some glue to the plastic paddle.
The final plan would be to replace the wire with something non conductive like fishing line and then make two tiny holes in the back end of an electrical box and hot glue the servo to the outside back of the box. This way the whole thing would be non-conductive should it break loose, and the low voltage servo and micro controller would not be in the same box as the high voltage switch... This also alleviates the problem of trying to cram a servo into a tiny electrical box.
I'm not 100% sure this is to code, but since all the modifications are non conductive and the LV stuff is outside the box it should be relatively safe.
I DO NOT RECOMMEND ANYONE TRY THIS AS IT IS PROBABLY AGAINST SOME KIND OF CODE AND TAKE NO RESPONSIBILITY IF YOUR HOUSE BURNS DOWN OR YOUR DIE!!!!
Here's a video of it in action: