do you use a grounding probe?

[mark]

It's not a big deal to put in a breaker or sort out the third wire but I would suggest if there's any doubt in what you are doing, probably best to call a electrician.

As for laws, as a home owner you are able to do electrical work yourself with a permit. Also my understanding if all you are doing is replacing existing, a permit is not required.

Still again, if you are unsure, get a electrician.

As for tripping when not around, rather I come home and find the tank off than the wife coming home and finding me dead.