2012 jayflight 26rks switching and slide lights not working

Most likely broken wires feeding the slide.

Since slides must move in and out, so, there has to be some slack in the wiring to allow this movement. Often done with a "curly cord" like you would seen on old fashion telephone handsets..

Might want to check on the underside of the slide for the wiring and then you will have to find the junction points to see where the breaks in the wiring may be.

Worst case may be if they hide the wiring in the walls or floor of the slide..