haha you can use the 555 timer. it deliver way more than 2 pulses a seccond. it can be adjusted to many hundreds of hertz, and thousands as well, im just not sure of the maximum. i uses a 555 to drive a large NPN transistor that drove 12v through a car ignition coil (at decent amperage) at around 10,000 hz, which resulted in about 2-3 in sparks being emmited from the ignition coil (ignition coils are in cars to make the spark plug ignite fuel)
annyways, this can be modified in that u use a small audio transformer, and u use alot less power, probably at most a 9V battery.
another way, it use use a photoflash circuit off of a camera. it charges the capacitor in it to about 300V, which give quite a nasty shock,
just becareful of anything wall powered, and rember the ONE hand rule... even 3 (three) volts at 20 Ma flowing through the heart can kill you, though thatemans that ud need quite the powersupply, as skinns resistance is several mega-ohms per inch, though 110 volts at 10 amps from the wall outles can do it quite nicely.
there is a thing that is called the "tickly stick. its odd, since neither is it a stick, nor does it tickle! it Hurts! its a small metal box desighned to shock people, made into a paperweigh to shock the curious. look on
https://www.jameco.com and order the magazine. its in with the "kits"