much more convenient than the current method of searching for leaks with a multimeter. Walk catch with or without land. Coupled with a polarity tester outlet, I could find why my subwoofer and snored my refrigerator: the painters had reversed neutral and phase winding catch! More "chestnut" touching my PC or HC amp box. Anecdotally, many power outlets PC type (IEC C13) as neutral and reverse phase, as many electrical doubles and triples. And it is not always possible to remove the wiring of a device to check.