This is my first instructible. I had just got my old nintendo from my parents house and the game wouldnt work so i tried to combine some parts that i had laying around. turned out pretty good and my cat loves it too. oh dont point the laser in anythings eyes. the diode is rated to 4.5 volts but i have 9 volts going to it so that might shorten the life a bit.
http://www.instructables.com/id/Nintendo-Zapper-Laser/