I'm looking to add an occupancy sensor switch in a staircase that has a pair of 3way switches. The power source comes in at the light, then goes to the switches, see Diagram: The main issue I've been running into is that all occupancy switches I can find needs either a Neutral or a Grounding conductor, both of which are not in my switch boxes (and not in the budget to be added). Reading up on the post below I noticed UMS-OPS6M-DV that says it only needs a 25w load to run. http://diy.stackexchange.com/questions/39853/is-there-a-motion-sensor-light-switch-that-does-not-need-ground What does this mean exactly? My LED lights run a Load of 18w total... 1) Will 18w work, if not I can increase the bulbs 2) Does this minimum load mean there is always (let's say) 25w being always used to just power the switch? Or why does this minimum exist?