first you must find a disposable camera. I think I used one with the brand name kodak. the reason this works is because of a component in the camera called capacitor. this component is charged, holds its charge, and then will quickly discharge. this of course is useful for the flash in the camera, so do not buy a camera without a flash. (I was originally going to make a flash bang by rewiring the shudders and flash, and by upping the voltage on the battery, but bought the wrong kind of camera, and got the idea for this after shocking my self while messing around with the circuitry. being shocked with this hurts, and it is dangerous so please be responsible and do not use this on animals people or flammable items.
I recently remade one of these with four of the capacitors in parallel. Got some amazing sparks with a deafening crack. here's a video:
this step is very easy. you just remove the cardboard/ paper from the camera and pry open the two plastic pieces that make the housing for the camera. do not throw them away though, I ended up using them for the housing of the stun gun although you could buy a project box from Radio Shack and it would probably work better.
Step 2: remove the mechanics and plastic from the camera
to take the picture many disposable cameras have a series of gears that must be turned in order to prepare the camera to connect two leads. all of these are useless and need to be removed. the lens and view finder will also have to be removed.
the only thing (other than the covers if you are going to use them to build the housing) you need from the camera is the circuitry. when you remove it from the plastic it is mounted on be very careful not to touch any metal parts on it. make sure the camera has the large capacitor, but if it has flash it should have this. next step soldering.
behind the cover for the flash there should be a thin glass cylinder that is about 2 cm long and is connected to two copper leads on either end of it. use a soldering iron to melt the solder connecting the cylinder to the leads, and remove it. Be sure not to damage the leads in the process.
the copper leads that used to be connected to the light bulb will be where the two wires of the actually stunning part are attached. take two insolated wires, and strip them up to about 1 cm on both ends. twist one end around the copper leads, and solder it to the copper lead. do this for both of the wires. make sure the ends of the wires that are not connected to the copper leads are left alone. do not connect them to anything. you will touch the item you want to taze to these exposed wires.
on the camera that I used there were two pieces of metal that went to the shutters that were not connected. using a wire about 5 cm long stripped about 1 cm on both ends you should twist one end around one piece of metal, and the other end around the other piece of metal. once you twist them around solder the wire to the two extra leads. Once this is done, you are done soldering.
to make sure it works, go to an area with no flammable items, put in the battery charge the flash, and holding a coin in pliers touch it to the two exposed lead, and you should see a large spark, hear a loud click, and then see two burn marks on the coin where it touched the two wires.
I used the two covers originally on the camera to make the housing, but you could make housing out of anything plastic (so long as it is an insulator it is OK). drill a hole where you would like the stunning wires to come out, and feed the wires through this hole. glue the circuit board coponent side up and line up the flash buttons on the circuit board and the front cover. glue it down tightly enough that you can press the flash button on the front cover and hear it click on the board. you can cover the covers in duck tape to make them look better. after this you are finished.