2 Outlet Light Socket Adapter, E26 Bulb Socket to Outlet Splitter,Converts Medium Screw Socket into a Socket with Two outlets,Polarized Outlet,with Pull Chain Switch. UL Listed, White (2-Pack) - - Amazon.com
Commercial Electric 1-1/2 in. Porcelain Socket with Ring 82205 - The Home Depot
Amazon.com: Nyce Power LampCharger Light Bulb Socket Adapter, Light Socket USB Charging Station, USB Charger Ports, Tablet and Phone Charger Adapter | 60W Max (Lamp Charger with 2 USB Ports) : Tools
Vintage On-Off Turn Knob Lamp Socket, Various Finishes - Royal Designs, Inc.