As an underage drinker, I often take alcohol from my parents liqour cabinet. I was home alone today and wanted to take some... but something happened. can anyone help me identify this object?

I opened up the cabinet, heard a little snap, and i found two small pieces of plastic that looks like it broke off. Is this a parental trick to know if a cabinet is opened? I can post a picture of the plastic pieces if needed. thanks a ton.

EDIT: http://imgur.com/5fNJ4

EDIT 2: FUCCCCCCKKKKK. well guys. see ya later.

EDIT 3: i did some deep thinking, and decided i am going to leave it broken, and not try to buy a new one. However, i am going to squeem my way out of this... Been talking to my mom all day. and at one point i asked her (over text) if we had any paper towels because i spilled some soda on my keyboard. I fratntically ran through the house looking for paper towels in every cabinet. (all this is true) i left the cabinet open alone with a few around it and the thing on the ground. i will let you guys know how this goes.

and also, to clear some things up... I am 18. I do not have a drinking problem and I only drink as a social thing. I see no problem in it, if thats not your opinion then that is okay. I am old enough to vote, and enlist to the army, i dont see why i shouldnt be able to drink with my friends.

My older brother (22) often took drinks from my parents, and i think that is why they are paranoid. the only problem they have with me drinking is i am not out of high school yet. (Yes, i am in 12th grade.) I take from them because it is safer. I will no doubt let them know when i graduate, and pay them back. thanks for all the help for those who were actually trying to help- for those of you who aren't or are on a high horse right now... just back off.