I am a primary school teacher organising a spelling bee, of which the final round is hopefully going to be like a quiz show on stage. 3 contestants must be able to hit a "button". The first person to hit, must switch on a light and a buzzer, and cut off the other 2. The light and buzzer must stay on just long enough so that the facilitator can see who is first. The design must be as simple and cheap as possible, and parts must please be labelled so that I will know what to buy (I am a language teacher, my science background is extremely limited). We plan to build a wooden box as container. About 100-150 children will attend the show.