Here is a quick sketch of what I understand so far. So my questions are. Where does the black hot go to? Does it follow the same conduit as the pool light? It appears to be a three wire (which explains the red and black sharing the white (neutral) and Green (ground). So at the light, are you seeing all these wires, red, black, white and green? Are there other wires seen here? Possibly a two wire line (white and black) bringing 120 volts in.