eden wrote:
Thanks for comments so far....

photos posted on flickr

http://www.flickr.com/photos/35218568@N03/

Have had a further dig and the green wire is connected to a metal
spike thing in the earth. Surely the cable will weather if exposed
like this??
yep. After 50 years about 10% of the unshielded copper in my parents
home had corroded away.

But it was in better shape than the original rubber in steel conduit
wiring ;-)