I want to install a new fan and light assembly. I removed the old one, which on the wall is a hard wired 2 switch, one for the fan and one for the lights. Coming out of the ceiling is a white, black and copper wire. I understand black to black, white to white and green to copper wire. This unit also has a blue wire for lights. Not sure where to attach this blue wire. I tried to put it with the other 2 black wires but that does not work. Any suggestions?