Kind of baffling. The body is hard plastic, it's 1cm long. It appears like it's a single wire embedded in the body, and something cut that notch out, ie that notch doesn't look like it was part of the molding of the plastic.
It measures open circuit, it doesn't change with a magnet. Not a reed relay. Measures as "not a part" on my RLC meter. All that is visible in the notch is the face of the cut wire.
As a spark gap it would suck since there's no pointy bits. As a coherer it would suck because there's no place for the filings...
I found it in a bag of resistors and junk, but this part might not even be an electronic component?