I am replacing an old microwave motion switch which controls my two porch lights. It was wired from a three position (on, off, auto) wall switch. Much to my surprise, the wall switch and motion switch are powered by separate circuits. When the switch is in the on mode, power goes through the wall switch to the lights and they are on. When in the auto mode, power comes from a separate circuit, through the motion switch, then through the wall switch to the lights and they come on when motion is detected. It may have been wired this way to allow the on/off/auto feature before the newer infrared motion switches provided this internally. My quandry is that the lights only have one neutral, which is through the wall switch. So, when in auto mode, the hot is coming from one circuit and the neutral from another. Is this kosher? If not, I'll have to run a new neutral wire from the wall switch to the motion switch.