I have a residential project replacing the receptacles and switches.The house is a 2 wire but it's all in conduit. Most of the receptacles are the usual 2 wire type but some have been replaced with a grounded receptacle using a ground wire from the receptacle to the box. I am getting a correct reading on my tester. Can I continue to run a ground wire from box to receptacle using a grounded type ,tamper resistant receptacle ? I'm assuming the conduit is bonded to something in the crawl space, i.e. a water line. Any comments ?