Hi, I live in tulsa oklahoma, I work for shadow mountain, also known as brown schools of oklahoma. My first question, is there a law stating you must receive a lunch break if you work 8 hours, and can they mandate what you do during that time. Employee's are getting wrote up for napping during there lunch time. We do not get paid for this lunch break. They give 15 min breaks paid if time allows. We are not allowed to leave the property, just in case a patient becomes unruly and our help is needed. There is a total of 14 people working this 11pm-7am shift.

Breaks and meal periods are not required by law in Oklahoma.
http://www.state.ok.us/~okdol/wh/WH-FAQ-2005-09-27.pdf

The mere fact that you are not allowed to leave the premises does not, in and of itself, does not make the meal period compensable, However, it appears from the federal definition of a bona fide meal period, that the employer prohibiting you from pursuing personal activities, which may include sleeping, would make the meal period compensable. You can contact the federal Dept. of Labor at 1-866-4-USA-DOL to inquire whether your particular situation (I'm assuming this is a residential facilility) qualifies as a bona fide meal period.
http://www.dol.gov/dol/allcfr/ESA/Title_29/Part_785/29CFR785.19.htm