Can you use this switch with an LED light that has a built in motion sensor?

If the motion sensor is actually part of the light fixture, you will most likely not have a good result when putting a dimmer on it. It depends on the motion detector, but many times this may cause the lights to flicker or become unstable. If the motion sensor is wired in to the circuit before the dimmer (and all it is doing is turning the dimmer on/off when it senses motion), then you should not have a problem using a dimmer in this set up.

I'm not positive but I would think not. My understanding is that some led lights are compatible and some are not. It should say on the package they came in. But add the motion detector and I would rule out the dimmer.