Have a nice spot to mount a rooftop antenna. Our new (to us) house was built in 2003, and looks to be prewired for cable, because it has a coax connector in every room. The problem is that there are at least 7 cables entering the house, 3 from an old satellite dish, and at least 4 from an old cable set-up. Is there any way I can find which one is the "magic" wire? Any trick or tool I can use to trace these wires? The attic is a spaghetti nest of wires.My best case scenario would be to feed all the rooms from the antenna to this one wire.