Amazon.com: UltraPro Porcelain Light Socket with Pull Chain Light Fixture, Light Bulb Socket, Medium Base, Indoor Lighting, Mount on 3-1/4” or 4” Box, 250VAC/660W, UL Listed, White, 18303 : Everything Else
RDEXP Vintage Lamp Socket with Pull Chain AC 110-240V E27 Light Bulb Edison Pendant Holder Switch (Antique Bronze) - Amazon.com
Phenolic Medium Base Light Socket with Pull Chain Switch,3 Pack TWDRTDD Black Period Style E26 E27 Edison Retro Pendant Lamp Holder (Full Uno Thread and Ring) - Amazon.com
Leviton Glazed Porcelain Lamp Holder with Pull Chain and Outlet R60-09726-00C - The Home Depot