Hi Cindy,

I only just picked up on this topic, so there's not much left that's not already been said. Just my 2 cents though.....

As the others have said, forget the idea that current ALWAYS tries to get to the earth/ground. Just try to think of the earth as another conductor which you can connect to by driving a rod into the soil. (O.K., so it's a very big conductor about 8000 miles across! [Linked Image])

If you took a length of wire, you could connect one end of it to any point in a circuit, and nothing would happen. It's only when the other end is also connected that current can flow.

With a circuit connected to ground at only one point, no current can flow to the ground from that circuit. It's only when some other part of the circuit is grounded (intentionally or by a fault) that current flows through the earth.

In practice, that common "conductor" called earth or ground is shared by many other systems, but that doesn't matter, because the systems are linked only at that one point. (e.g. If you drive two cars together so that their bumpers are touching, both cars' electrical systems still function perfectly well, because there is only one point of contact between the two.)

We have an example of an ungrounded circuit in many British homes: It is used for an electric shaver outlet in a bathroom.

The standard (in Britain) 240V supply has one wire grounded, as in the States, so if anyone were to touch the hot wire while holding onto, say, a faucet, he would get a shock. Yes the current is going to ground through his body, but only because the ground (and pipework) happens to be a convenient path back to the neutral of the utility company's transformer.

To reduce the shock risk, the shaver outlet in a bathroom here is fed by an isolation transformer. The primary connects to the standard 240V supply with one side grounded.
The secondary is also 240V, BUT it has no ground connection to it. It's possible therefore, to accidentally touch either side of the outlet and a faucet at the same time without getting lightly frazzled, because the path through the body is then the ONLY connection to ground on that circuit. (You might feel a very slight tingle, due to the capacitance effect that Scott mentioned.)

In fact, you could take a length of wire, ground one end to the faucet, and shove the other end in either side of the shaver receptacle, and nothing would happen: No big sparks, no bang, no blown fuse. Again, the circuit has only one point grounded.

The fact that the shaver supply is ungrounded means that the only way to get zapped by it is to touch BOTH sides simultaneously -- Much less likely to happen than contacting one side while grounded.

I hope I haven't confused you any more. Merry Christmas!