I have a Greenlee "POWER FINDER" and it is a life saver. It is expensive but the time it will save you is immearsurable. If you do alot of fire alarm installs as well this thing is great. You will hear the toner through the speakers to help you know you are somewhat on track. Great for detecting shorts to ground as well. It is expensive but that will disappear once you learn what it can do.
[This message has been edited by elektrikguy (edited 07-01-2002).]