Commercial Electric 2-3/4 in. Brushed Nickel 3-Way Turn-Knob Socket 7040600 - The Home Depot
Wired Lamp Socket, Brass - Brown Cord - Paxton Hardware
Zevnico E26 E27 Light Sockets, 8 Packs Edison Period Retro Style Pendant Lamp Holder, Replacement DIY Pendant E26 Medium Base Screw Light Holder, Maximum Wattage 100W, Vintage Black Light Bulb Socket -
Project Source 250-Watt Plastic Turn Knob Lamp Socket, Gold in the Light Sockets department at Lowes.com