How to change 2 prong outlets to grounded in 40 year old house?

Lets not run to re-wire so fast. A grounded system is a great idea. Especially for safety, not to mention computer grounding, stereo equipment, etc. that is susceptible to static and free electrical problems.

You need to find out if the wiring was ran through shielded conduit to a metal junction box where your plug is located. If so many times the conduit can be grounded.

As is always the case, and as mentioned above, you and your family's safety is the first concern. Spend the money and call in a licensed electrician who specializes in remodeling. Too many sparkies only do new construction and are not electricians - they just work under one whom may or may not be on the job-site.

Furthermore codes are so different from area to area. What works in Illinois, does not in California, and may not work in Alberta, or Japan.

Best of luck to you with your new home. - DAVE

Sadly, you must rewire the entire part of the house that needs to be grounded. You should take one of the 3 pronged outlets' cover off to make sure it is actually grounded too. Someone may have outsmarted themself and tried to "fix" the outlets by putting new 3 prong outlets and only using the two existing wires. It isnt that difficult to rewire a house though, you just need someone who is qualified to work with you.

Method one - Your going to be replacing wire. Buy some new 3 wire cable. Go with 12 gauge. Pop the breaker out and disconnect the old stuff at the service panel and all receptacles. Use the old wire to fish the new wire through your floors and walls by duct taping the hell out of and pulling it through. Make all necessary connections and discard the old wire. Method two Replace all 2 prong receptacles, fish ground wire through to all ungrounded receptacles with a fish tape so all are connected together, and finally fish through to the neutral bus bar on your service panel or to a grounded outlet downstairs and complete the connection. Either way your going to be cutting out some sheetrock and/or drilling holes. Hope this helps.

Please get "Grounded"

we just lost to kids in a lake in De Soto , MO......by Electrocution. Its still under investigation...The Whole lake is "Alive"...theres a groung prob some where.. Faulted ground Kills. What Happens is that if by chance someone comes into contact with an open AC receptalcle "They Be come GROUND" and it hurts if not kills