When I was in 7th grade, I ran for school treasurer. I don't remember the signs and stuff that I made, but I sang my speech (based on the AT&T commercial featuring Whitney Houston with "Your True Voice") and that turned out to be a crowd pleaser -
I actually ended up being treasurer of everything until I graduated from high school. If you can't sing, maybe try coming up with a fun and creative speech versus the "You should elect me because I'm such a great person..." at least people will remember you, and thus, vote for you.