I have a peculiar situation. My LED light is fully dimmable down to 10% per manufacturer spec (this light). To test its function, I hardwired the light to a plug (like this Plug) via a dimmer switch (this ), and plugged into a wall receptacle. It dimmed nicely. So I then hardwired the switch to a 15amp feed in a box. The light turns on and off, but doesn't dim. What could be the cause?