I Need A Phone Exorcism

A couple of months ago, I traded in my old phone for a Samsung Galaxy S6 Active phone and if things keep on going, I am going to be arrested for being a serial stalker.
Even though I turn my phone to the sleep mode by pushing the little button on the side of the phone.
But as soon as I put the phone in my pocket, it turns on, will go to different apps and it will go to the text message and phone apps as well.
As far as the phone goes, my kids and wife and anybody else on my contact list get numerous phone calls through butt dialing.
I will also send numerous text messages to my contacts and the messages are quite strange.  Sometimes words will be formed and other times, just scrambled letters.
And that is just my contacts.
My phone has also called strangers throughout the U.S. and who knows where else.
Out of the pocket, there have times when I held the phone in my hand and all of a sudden the phone starts to dial a contact.
So, my phone is in need of an exorcism or some kind of fix, otherwise, I will probably be accused of stalking someone.  I don't think blaming my phone will help.