If you want some suggestions on how to stop this, you can :-

a) always take initiatives yourself and come forward to switch those switches
b) you can inform the student council or some other authority regarding this issue      and take their help for creating awareness among the students
c) you can create awareness among your friends and encourage them to conserve energy
in case ur question is something else, do let me know, nd i would love 2 help :)
Put posters in your classroom and around the campus containing messages regarding the importance of saving power and electricity.
Conduct workshops to enlighten students
yup that could be another alternative