Step 1: Get the Board
Get this simple taser board from an electric fly zapper. It's cheap and only needs 2AA. Ours was really old so the zap was not nearly as bad as what you would buy today.
Find a Fly zapper.
Find a project box.
Find a switch.
Put switch on project box and hot glue.
Drill holes for metal rods, and make it all fit together snugly.
Step 2: Make It All Fit
We used a different battery pack that did not come with our fly zapper. This is why we have 3AA and not 2AA. Either way it'll shock you more :)
Hot glue battery pack and board into box
Step 3: Zaaaaaaappppp
You have completed in making the taser.