I have an old electric menorah from which I removed an ill-fitting white ceramic wirenut to replace it with a better fitting but garish yellow plastic one.
Some people also call them "marrettes".
The one I removed, however, is unglazed. There is also no metal spring inside the porcelaine shell and no maker's mark -- just a UL logo on the top.
I saw, years ago, some tiny ceramic wire nuts in a lighting store here in New York. Didn't know they still made them in that material.
