What are some decoration ideas for a Techno Bubble dance?

At my school, we have started hosting a casual "Welcome Back Week" Dance. It's jsut to welcome everyone from summer back to school,a nd get everybody involved, introduce new teachers, etc. Throughout the week we host a mini spirit-week, with games and dress-up days, and on that Friday, we host a Dance for about $5 a ticket. We always do a black light dance, with bubbles that glow on clothes and skin once popped (it washes off normally with soap and water). The company we go through also does glow-in-the-dark face paint. Anyway, this year's theme for the week and dance is "Clue", the murder mystery game. I'm in charge of decorations for the dance. And I'm having trouble coming up with a way to decorate our gym (with bleachers and and basketball nets and all) cheaply. Seeing as tickets are meant to be a small fare, I can't have anything too elaborate. Any Ideas?