MRC 2006 Michigan Residental Code. NEC covers replacement Receptacles under 406.3(D). AS far as MRC Chapter 39 Devices & Luminaires. E3901.11.1 Exception. That deals with grounding switch plate enclosers,& Switchs fed with ungrounded Romex GFI protection can be used. Section E3902.2 says 15 & 20 amp recp. SHALL be grounding type. I could find nothing of Outlets & existing. Might be best to ask yout AHJ if he is going to use the NEC .