Didn't see it mentioned, (Yep, someone did mention it.) but have you isolated the circuit this current is from? Like by shutting things off. i.e. circuit off, no current, and vice versa. Just to locate the source. ( Or whole house off, its outside. ) Then you can break up that circuit in sections to isolate further. Then, and I'm not sure you can do this with some of the ring methods used in other than the US. But you might be able to pin-point further with a graphic TDR.
[This message has been edited by e57 (edited 01-23-2005).]
