Outlet to Socket Adapter,Plug-in Light Socket,Convert Outlet to Light Bulb Socket,Polarized 2-Prong Outlet to E26 E27 Screw Base Bulb Socket, 660 Watt, 125 Volt, UL Listed (4-Pack) - Amazon.com
Source VDE halogen G9 LED electric light bulb socket ceramic/porcelain lamp holder with plastic thread on m.alibaba.com
Leviton Outlet-to-Socket Light Plug, White R52-00061-00W - The Home Depot
10pcs mini light bulb light bulb holder Small Lamp Holder for Labs Small | eBay
Remote Control Light Bulb Socket, Wireless Light Switch For Pull Chain Light Fixture, Remote Light Socket E26 E27 Bulb Base With Wall Mounted Wireless Controller, No Wiring - Temu