[AC Question]

I went to sleep last night but my phone woke me up because it started making a bunch of noises (even though I keep it on silent at all times). I looked at my phone only to discover that it had been going through a bunch of apps and taking hundreds of screenshots, looking through emails and chaining my system settings. For example I had turned off my wifi just before going to bed and it was turned on when it started to make the noises. My blue tooth was also turned on and I never use that at all. It also changed settings that were not in the bar at the top, like changing my keyboard to one handed mode. There wasn't any wifi that it could use, so I don't think that it could connect to the internet. It didn't just open apps that I had running, it also opened apps I had never used like google hangouts. When I left my phone to go to sleep I had it charging, locked (Without a password) laying face down on my closed laptop (It was not on). I installed AntiVirus Security - FREE from AVG Mobile to check if I had a virus of some kind and nothing showed up.

[B. Diddy]

Welcome to Android Central! Strange behavior. Try booting into Recovery and wiping the cache partition, which won't erase any personal data: Reset: Samsung Galaxy Note 3 | T-Mobile Support

[Rukbat]

And if that doesn't fix it, and it's still under warranty, bring it back to TMobile and ask for a replacement.