Wire Tracker and Ethernet LAN Network Cable Tester for Network Cable Collation, Telephone Line Tester, Continuity Checking RJ11 RJ45 Cable Tester Line Finder Multifunction
cabletracker - YouTube
WirePulser: A DIY Wire Locating Tool - Blog - Test & Tools - element14 Community
Build Your Own LAN Cable Tester | Hackaday
How to make a cheap Cable Finder - DIY Tutorial - YouTube