But just because the GFCI has a hole for a third prong, don’t assume you can plug in three-prong plugs.
The National Electrical Code (NEC) states that any appliance equipped with a three-prong plug is required to be grounded, and the installation shown does not provide the necessary equipment ground.
Update 2: I purchased a receptacle tester and the receptacles all show which seems to indicate that they are wired correctly. Update 3: Ok I plugged in the multimeter and it only goes to 30...
to make sure my multimeter wasn't out of whack I plugged it into my working outlets and the needle went to 120V.
Increase the safety of your old two-prong outlets by installing a new ground fault circuit interrupter receptacle.
The GFCI will protect against a deadly shock, even if it’s not connected to a ground.
Update: I opened up one of the plugs to see if there was anything visibly wrong.There are so many on the market, in fact, that it can be a bit bewildering to pick through them all and decide which to select.Let’s take a look at some basic considerations to ensure you get not only the right outlet for your needs, but one that will keep you and your gadgets safe. In short, it’s an electrical safety device designed to prevent fires.It looks and acts a lot like a GFCI device in that it has a test button and a reset method, but GFCI devices are designed to prevent people from getting electrocuted, not prevent fires.I attempted to plug a small test lamp into the new receptacle without fully screwing it into place and a bolt on the hot side that wasn't fully tightened brushed the side of the metal box thingy and caused a spark! I'm guessing that means the power and the ground are working.