Do you have ungrounded receptacles in your home? Without a ground there is potential fire / shock hazard.
In pre-1950’s homes, ungrounded receptacles (either two prong or three prong) are an indicator that knob & tube wiring may be present, however it should be noted that the next generation of wiring was also ungrounded. A newer home with grounded wiring does not necessarily mean a receptacle is grounded either. For personal safety, ungrounded receptacles should only be used with appliances / devices requiring same. Devices / appliances with three (3) prong plugs or polarized plugs should only be used in conjunction with appropriately wired & grounded three (3) prong receptacles and or ground fault (GFI) receptacles. GFI do not require a ground wire. Having a 3-prong receptacle is NOT an indicator that the receptacle is grounded and should be tested to confirm its presence.
Click here to learn more about ungrounded receptacles, polarized plugs & reverse polarity.