I have the same problem and I'm pretty certain it's NOT related to bad switches - let me explain.
We have LUTRON switches through the house. All was fine. We then had a minor 2nd floor renovation creating my wife's walk-in closet. LED's were installed in the closet. In the kitchen on the 1st floor which never had any issues, we always had LED's. We started noticing the lights in the kitchen would go on/off with 1/2 second intervals - couldn't figure it out. The renovation occurred during the summer so we didn't connect the lighting issue with the renovation because, being in a northern climate, it was bright and the lights weren't needed. We then realized in the winter that whenever the lights in the walk-in came on, that's when the on/off occurred. I would add that its NOT a flicker - definite on/off; I would also note that the walk-in switch is a sensor switch.
We were just living with it. Then we created a media closet - I screwed in LED bulb - then all of a sudden the LED pot lights in the adjoining hall started to do the same thing! Off/on. I switched the media closet light back to incandescent and the problem ceased. I would add that the media closet switch is also LUTRON sensor.
Q: Any thoughts? We have a few sensor switches as well as regular touch switches and LED for all pot lights though some fixtures are regular halogen/incandescent.