My phone has now accidentally called several people while I was looking at contacts. It even dialed my parents and my wife once while the phone was sitting comfortably in one of my cargo shorts' pockets. It also has the irritating habit of clicking on stories or adds that I am not interested in while on social media.
When I looked up the problem, I discovered that the iPhone 6 plus (which is what I have) has a faulty hardware component that frequently causes "touch screen disease." Apple claims that it comes from the phone being dropped too often, but I am really careful with my phone and have a nice case on it. It seems more likely that it was shoddy work that should have had a recall and a fix.
I plan on just living with the issue for the time being. Most of the time everything works fine, and on the few times that it doesn't, I can usually do the quick fix. It's just another one of those first world problems ...