Difference Between Grounded VS Non-Grounded Plug Cords
grounding - What is an ungrounded extension cord? Is it dangerous? - Electrical Engineering Stack Exchange
Extension Cord Grounding – A Detailed Guide – PortablePowerGuides
Is it safe to use an extension cord with a three pronged but groundless electrical outlet (no ground wire)? What should be done in such cases if they are encountered? - Quora
HDX 3 outlet 6 ft 13 Amp 16 gauge indoor Extension Cord in White | eBay