Dangers of a Grounding Conductor
The copper rod looks like a grounding conductor, typically located outdoors amd pounded 8 feet into the earth.

In some juristictions newer code allows (or even prefers) the rebar frame within the foundation to be used as a source of ground instead; this conductor could be connected to that.

No current should pass through any grounding conductors under normal circumstances, but if there is a problem they can carry full line voltage, and current up to the limit of the breaker or fuse protecting the problem circuit.