Picked up my rope lights this week and all but one string will be hardwired to electrical rather than using the standard plug. I had a cheap "sacrificial" strand to inspect, and unsheathed a chunk of the roughed in wire in my theater. Here they are: I'm pretty sure I can figure out white-to-white and black-to-black. However, the wire roughed in throughout my theater has an additional ground with no partner in the rope strand. How does this fit into the equation?