wrote in message
ups.com...
I'm in an old apartment and I'm rewiring my receptacles because they
have no ground. I have some odd situations.

Most are two prong receptacles, but some are 3 prong. I tested the
voltage on them. The 3 prong I tested showed about 60v from ground
screw to the small slot-HOT and60v from the ground screw to the large
slot(NEUT).

There is no way you can get these reading legitamately. My guess is that
ground screw is not grounded and the 60v is phantom voltage.

Also, 120v from the small slot to the cold water pipe.

The two prong showed 101v from the large slot to the radiator pipe,
and 0v from the small slot to the radiator pipe (wrapped a piece of
copper wire around the corroded valve stem).

Now, the large slot is supposed to be neutral and 0 volts to the
ground/waterpipes/etc. and the small slot is suppsed to be hot.

Question is 1) Would it hurt to rewire the recepticles to large-
neutral, small-hot. I'm imagining a situation where one day I plug
something in with the ground and hot shorted... What should I check
and look out for?

Yes, once you make certain you know what you are doing you should reverse
them.
I just don't have much confidence in what you are finding.

and 2) what's the best way to run the ground wire? I think it's tacky
to run a 12ga (black insulated) from the green screw on the new outlet
outside the outlet cover, along the baseboard to the radiator. How is
this *supposed* to be done?

To meet code you have to run a wire back to the circuit box, going through
all the same holes as the other wires. Even that might not be enough, but I
can't see your wiring.
It is debatable if a wire to the radiator is more or less safe than nothing.