never seen this before
I guess being a "wrench" is kinda like being a doctor. When at a party, and someone finds out that you do what you do for a living...
Anyway, a neighbor came to me with this; He has an '07 ford pickup, with the triton V-8 5.4l. It developed a misfire, so he elected to change the spark plugs. Now these are not your ordinary plugs. these things look more like an igniter for a stove, or a "torpedo" heater. Anyway, he found the culprit, and went to extract it, all came out except the part marked in the pic. it's still in the head, with the ceramic, and electrode still in it.
It's like it just snapped off at the base of the tapered part. (probably the reason it quit firing)
The picture is of one of the other plugs that he replaced @~$13 ea.
The part between the lines is all that's stuck in the head.
I've been delegated to come up with a method of extracting it, without removing the head, or ruining the rest of the engine.
I've gotten pretty good at removing the threaded parts of broken/seized plugs, but this is a new one on me.