What is the current path in an overcurrent fault condition?

The current path in an over current fault is the path of least resistance. Older electrical systems used to use the neutral wire for this purpose. It was found that on some occasions this was not the path of least resistance. Hence the installation of a ground wire being installed in cable sets. This innovation caused the whole grounding section in electrical code books to be rewritten. Now a specific ground wire is used to bring the fault current back to the distribution panel to trip the breaker and open the faulted circuit.