Ive recently bought a house in downtown San Antonio built the late 20s... The price was too good to pass up. For its age its a survivor. Its built on pier and beam with paver brick exterior covered in 1/2" cement with a 1/8" stucco type topcoat. 3 bed, 3 bath, study, dining, utility, living room, gas throughout with a fireplace and detached garage. Now my question is about grounding an old circuit. Originally the house had an old, 4 glass fuse box. At some point, (probably 60s or 70s), two more grounded breaker boxes were added outside. A main and a sub panel. Currently, it has a main 220 box with four 220 breakers. It feeds the grounded exterior subpanel, and the old interior non grounded subpanel. The old non grounded fuse box has a dedicated refrigerator plug... nongrounded. Im redoing the cabinets and am not needing that plug there anyway so I junctioned in a 12g romex and ran a series of two plugs then the refrigerator plug. 3 plugs total. I have all the ground wires hooked up and was thinking about running a 12g green wire to the grounding bar on the outside sub panel. Will this work and ground the outlets safely? And if it will work, can I tie in multiple circuits and pigtail them all back to one ground on the grounding bar?

I'm in the middle of bathroom remodel for a customer. The house is build in 1954 and wiring in the bathroom is old BX cable without bonding wire and all junction boxes are metal. I am to install 2 wall lights and a bathroom fan/light combo. I checked if junction boxes are grounded, but they are not. Measured 6 Mohms between neutral and the junction box. I know that metal sheathing of the cable without bonding wire cannot be used and ground conductor, but using metal junction box through out the circuit will naturally ground junction boxes. However, it appears someone rewired something wrong or metal sheathing have corroded or oxidized and caused break in ground (that is why bonding wire is required I guess. :D). A previous electrician (or handyman?) installed recessed lights and a GFCI outlet but did not connect ground wire to anything. Just left it in the junction box. Funny how they connected a bare copper wire on GFCI and just left it in the junction box. Both light and GFCI outlets are on the same circuit, but lights are not GFCI protected. All new wiring I pulled are wired with NM-B and bonded ground wire to the metal junction box. My worry is that if wire insulation fails (very likely to happen since wires are old) or something fails in the light or fan, all metal junction boxes and metal sheathing may become hot. Not too worried about the switches since I will be using plastic covers. But lights have large area of exposed metal and they are mounted pretty low (on the sides of medicine cabinet). Is this situation still considered safe enough since it is old house? Should I connect light circuit to load side of the GFCI outlet? Because outlets for a bedroom next to the bathroom is taped from the switch junction box, they will be on GFCI as well if I do so.