Really weird home button issue with iPhone 5

Ok so this is a lot easier to show people than to explain it via typing, but basically the area to the left of my home button (the blank area that is not a part of the touch screen) is now functioning exactly the same as my home button does. Press it, even lightly, and it closes apps, opens the menu, it has become a perfectly functioning home button, which is extremely annoying. My actual home button still works fine. I have only had my phone since last Christmas (so about 6 months). Also, Siri has taken to turning on randomly, literally even if it's just sitting beside me completely untouched, it will turn itself on at random times. So yeah. Any advice, other than taking it back to Apple and hoping they will replace it on warranty?