On 15 Jul 2018, dpb wrote in alt.home.repair:

http://rednoise.vacau.com/temp/switch/

www.newark.com
www.digikey.com

Oftentimes such are OEM-specific so you have to find something
that meets function rather than specific 1:1 replacement.

It would be helpful if there were a Leviton part no besides the
ratings; what they show is you need something rated 3A @ 125VAC.

I see no part number, but you may be right about it being an OEM part.
"Leviton" is embossed on the plastic/Bakelite back, but "UND LAB INC"
is engraved on the metal, and that appears to be an actual company
name. I sent an email to Leviton, but don't really expect them to
respond. Meanwhile, I will cook wearing my miner's helmet.