I feel like you are getting ready to learn a lesson. ID doesn't trust the electrician = red flag #1. You're not a lighting guy = red flag #2. ID wants it to be perfect while asking a newbie to handle it = red flag #3.

I would ask myself these questions...

1.How much money can I make doing this?
2.What could go wrong?

Sometimes it's better to say "Im not a _______guy" (fill in blank with service of choice like "lighting"). This way you don't have a client angry with you for something you make $0 on...or worse...something you lose $ on.