I've noticed whenever I'm charging my iPhone 5S and I go to touch the home button, sometimes it gives me a little static electricity shock. It's happened a few various times when I've touched the charger (plug in to phone part) while unhooked. Also, if I touch the screen, it occasionally gives me a shock too. The phone is in an otterbox, if that makes any difference. Of course, I always have a lot of static electricity lately and all. So is more a matter of me, or the phone? And it only happens when charging. Is this normal?