High School GUYS: What would you think if a girl did this to you?

What if a girl you are mutual friends with put a card in your locker stating how she feels about you and signed it as "a secret admirer :3"?
Would you think she is stalking you or that she is weird? Would you try to find/pursue her?

I'm thinking about doing this to a guy that I REALLY like.
We are both freshman in high school and I just want some opinions from other high school guys:)