First up, a cheeky contender for Arc-Switch, as visualized by Blender.
The upper and lower chrome-bits are 1/4 teaspoon measures.  Stainless steel, about 1.5mm thick metal.
The arc-switch is in cross-section.  The hole in the PCB passes the arc, the copper shroud supporting the electrodes is soldered directly to the PCB copper.
Scale?  The arc-length is about 3/8", or around 8mm.
PCB is 6" x 9", 1/32" FR4, 1oz. copper cladding.

Here we see the 'top' traces on the PCB.  1/4" edge border, 1/2" A-B separation.

 And here is the ground-plane.

Shroud soldered onto upper traces.  Shroud pattern artwork courtesy of "ConeCalc", freeware.

 And here we witness my God-like soldering skills.  Spoon-trode soldered into shroud.
Caldera-trode?  Volcano-trode?  Fun stuff.

 View of the top electrode, from the ground-plane.  If you look real close, the solder-seam is visible.

Well, there are more photos to take, notes to crib, rumors to quell.
Laters.