What You'll Learn
9. UNGROUNDED (2-PRONG) RECEPTACLES
What it means: Your house's wiring has no way to safely conduct any stray current that escapes the confines of the wires.
Code violation? No; grandfathered in. (Today's code requires grounded circuits and receptacles.)
Danger level: Minimal, as long as you don't use an adapter to fit a three-prong plug into a two-prong receptacle. Doing so could destroy the device you're plugging in, and increase the chance of electrocution.
Solution: Replace two-prong receptacles with properly grounded three-prong ones, if wiring allows it (see . Also, test all existing three-prong receptacles with a GFCI circuit tester to make sure they're grounded. Rewire any that aren't.