What happens to an electron when he returns home after doing his job?
It depends on the mechanism which made the electron to move. You should notice that the generated fields do the job, electrons only move how they are forced. Their movement carries the field along the wires as we understand the conductivity.

If it happens that your electron has started his trip from a chemical battery and survives the whole current loop back into the battery without becoming trapped for another job during the trip he can very likely settle to a lower energy orbit in the lower energy end product in the battery process. If a generator pushes the electron to move he very likely returns to the same category orbit where he was catched from when the generator took him.

As others have already said electrons are only supposed to exist because their existence is a good looking explanation for many phenomens. Writing a story of an individual electron is useless, because observable macroscopic effects are based on the statistical behaviour of billions of trillions of electrons.