Cheater plug
ELECTRICAL ADAPTER FOR CONNECTING A NEMA 5-15 PLUG TO AN UNGROUNDED NEMA 1-15 RECEPTACLE
Three-prong adapter; Two-prong adapter; AC ground lift; Ground lifter; AC ground lifter; Three-to-two-prong adapter
A cheater plug, AC ground lifter or three-prong/two-prong adapter is an adapter that allows a NEMA 5-15P grounding-type plug (three prongs) to connect to a NEMA 1-15R non-grounding receptacle (two slots). They are needed to allow appliances with 3-wire power cords to plug into legacy ungrounded (two slot) receptacles found in older buildings.