It is perfectly okay to run a makeshift ground wire from the receptacle, roughly (for example exposed along baseboards) following the route of the wiring and back to the panel.
If this ground wire reaches the grounding electrode conductor (the fat bare wire from the panel to a ground rod or water pipe) first, it may stop there.
(One morning on WRKO Radio) The tub's not clean! Let's remodel the bathroom.
(One afternoon on WRKO Radio) It's time for an oil change. I'm going to trade in the car for next year's model.