i was playing with my little projectors last night - i have two of these Minolta Mini-35's they're very simple, tiny and cute. does anyone with experience of such things know how i might go about finding out what type of bulb they take? i took it out and looked but the bulb has no writing on it. is a high power filament bulb, bayonet fitting, tall and thin. ie. it doesn't look like either of these sort.

more importantly, i switched on one of them and there was a sudden BANG and then darkness. i thought i'd blown the bulb, but no, i took that out, seems fine. the fuse in the plug has blown. i am a little clueless with electricals - why did this happen? it's a very simple device - not much more than the bulb, the switch and the plug. what would cause the current to jump? was i close to electrocuting myself? is it just one of those things that happens from time to time, or does it mean something's wrong with the set-up?
the evidence is this: opening up the switch (in-line with the power lead to plug - has a little lever that connects the through wires or not) the wires to the plug-side of the switch are burnt, the plastic sheath to them is a bit burnt, some burnt marks to the inside of the case (and on my thumb). there are only two wires going through the switch. should there be three?

i'd be grateful for any help.