All you need to achieve around 1kV of shocking power is a relay, a 22nF capacitor, a 5 Ohm resistor and a big ass inductor. The relay is set to oscillate, causing current changes in the inductor and therefore huge voltage peaks.
All parts can be easily savaged from old electronic devices.
Pretty nasty shocks are assured.
This is a similar circuit to the one used in prank pens, the only difference is the inductor and the relay are often comprised in a single component, using the magnetic field for both actions.
