I am trying to install the HS 200 to a light switch that controls a power outlet.  The HS 200 has 2 black, 1 white (common) and 1 ground.  The plug has 1 black, 1 white and 1 ground.  The existing switch has both the black and the white connected to it.  Am I safe to think the black is the hot and the white is being used as the passthrough hot?  If so do I connect the HS 200 black to the black, the other HS black to the white, the HS white and ground both to the ground?