Probably the capacitor for the flash?
Those can give a jolt of several hundred volts when charged (the one in my old SLR flash was 660V)
(localboy purveyor of pisspoor puns, Fri 12 Aug 2016, 17:14, 2 replies)

Old sinlge-use cameras make good "TASER"s, apparently.
I've never had the wherewithal to attempt to create one, sadly, but it seems feasible enough.
(Me, I'm not... in any way intoxicated, Fri 12 Aug 2016, 19:03, closed)

Oh it'd work alright
I once wired two together for a specific effect, but forgot to tape the wires properly. Which terminated at the hot shoe, directly above my eyes. I wore metal framed specs. You can guess the rest.
The headache lasted a good 12 hours......
(localboy purveyor of pisspoor puns, Fri 12 Aug 2016, 19:16, closed)