You probably don't want to hear this, but a factory reset is going to be your friend. Also if you have 4.3 note that apps like Netflix, snapchat, and chromecast are causing these kind of issues right now and should be uninstalled. The app devs are working on updates. Usually apps are the culprit here, any new apps or updates that you have installed recently could be buggy, read the comments on the playstore see if anyone else has issues. Good luck!