Does ANYBODY believe that a device that shines light on your owee, or one that shocks your muscles, can QUELL pain???

I avoid 'beliefs' on certain things.  This would be one of them.  If evidence is there I'm happy to see it, but otherwise, count me out.

Pain is a curious phenomenon, because it is a neural INTERPRETATION of nerve signals (or, sometimes, the absence of nerve signals, as in "phantom limb" pain).

While I am skeptical of ANY medical procedure which hasn't been subjected to fairly rigorous testing (because the placebo effect is SO powerful), I won't dismiss the possibility of light or electrical stimuli altering how our brain interprets nerve signals and generates the experience of pain.

I'd say it might.

Light and electrical stimulation are all forms of energy; and we humans normally react to external applications of energy to our bodies.

I can think of ways it might work.