I’m in high school. There’s a girl in one of my classes that I ignore for the most part. She has tried throughout the year to squeeze my nipples while walking by. I don’t think she is doing it to be funny because I try to not react to it. I just am not sure if this could mean she likes me.
LemonVibe 
[Sure, it can mean that she likes you. And the only way to find out is to talk to her.
[It could mean she likes you; however her method for expressing it is quite odd for someone in high school, but then again while I was in high school there was a girl you would try to kick me in the shins during certain passing periods when some of us would gather to hang out for a few minutes. The between my experience, and yours, is that I was friends with this girl already and it was just a friend giving me a hard time because she would get a reaction out of me.
If you happen to like this girl…I agree with Dennis and you should talk to her.
[that is an interesting way to reach out to someone! i never tried that method, myself, but i would guess she has some sort of interest in you (unless she goes around grabbing everyone’s nipples?)
i agree with the guys: talk to her. say “hi” say anything. that’s the only way you will ever find out.
good luck!