I moved into a house with an automation system. The previous owner had ran extra cables from the attic down to the basement. I now need to use some of these cables. I had a guy here doing some work months back and he had some tool that he would clip on the wire and then go down to the basement where the wires ended and touch around with another tool till it started beeping and he knew that was the end to the wire he had clipped up stairs. Does anyone know what the name of this tool is? Or is there some better tool that I can use? I have a bunch of CAT5 cables that Im trying to find the beginning and ends of.