Thanks for taking those tests.
It looks like you need a new fuse. You can get one from us, but you’d probably be better off finding one locally…it’s a pretty generic part. You need to get a 1A, 250V fast-acting (not slo-blo) fuse. I think 15mm is the length, but you can measure that yourself.
Next, your pcb needs some help. But before we get to that let me ask…when you measured the 122V (am i correct to assume AC voltage?) on the switch, when was that? Was it before or after the fireworks? Was it plugged in to the wall when you measured that? It would be helpful to know this before we proceed with the pcb repair
In the meantime you can check out the switch to make sure it is still working correctly. With your meter still on the continuity setting measure between the switch’s middle pin and both the outside pins (one at a time). It should beep while touching one outside pin, but not beep while touching the other. Flip the switch and test again. It should now be just the opposite…it should beep on the other pin now and not beep on the pin it beeped on originally. Let me know what you find (or if this is too confusing).
Good luck.
-brach