I am adding undercabinet lighting. I have run all wires to the switch that I have added next to an outlet. The outlet has wires coming in and going out, meaning the outlet is in the middle of the circuit. How do I get power to the switch to turn on just the lights?

Run cable from outlet box to switch box.

In outlet box hook black from switch box to existing black in outlet box. Hook white to white.
Hook ground to existing ground.

In switch box hook black from outlet box to screw on switch and black from light to other screw.
Wire nut whites together. Wire nut grounds together with pigtail from switch. Hook grounds to box if metal.

Good luck

Chuck