Oak Switchplate Covers

Showing the twist applied during assembly of the switches to the plate

Now they are sunk back from the switch plate.

checked it with tester, all connections were OK, but the black wire + did not show any electic load in it. looks like it is disconnected or cut from the source that it comes from. How can I fix it , and usually where is the other end and source of the wire so that I can repair it. All other outlets and switches in other rooms are OK.

Short video of DIY CNC machine cutting a plastic plate for stereo controlls and ballast switches.