Elizabeth, yes, basicly a "short", I means bare wires (or wire and metal conduit) touching. Hopefully you wouldn't have put both wires on the same side of the outlet :-). If the insulation is very old and brittle, just moving it around could have cuased it to crack and expose bare wire, which may then touch the conduit and cause the breaker to trip. Inspect the insulation carefully for cracks. Look for any blackened or melted looking places. If the wire is pretty bad, you may need to replace it (not too bad a job when you have conduit). Try leaving the receptacle off, cap the bare wire ends, and turn the breaker back on, if the breaker still trips, the short is probably just inside the conduit; you'll need pull in new wire. To verify this, you can go up the line to the receptacle that feeds the problem outlet and disconnect the wire going to the bad outlet, then test again, the breaker should not trip. The "gotcha" here is that disturbing the wiring at the other receptacle could cause a similar problem.