Yeah, the bottom of the mirror box...yup...that's where the nifty parts of the AF system are located.
Have you noticed any strange orbs in the night skies? Have you had dreams of being taken aboard an alien craft--of any kind? Has all of the food in your refrigerator suddenly acquired the taste of,say, weird chemicals,like those that aliens might have left behind after a midnight munchies raid on your food supply? Do you ever think, "Am I really on Earth, or is this maybe another planet where aliens have taken me after they melted my Canon's AF sensors?"
Does the persistent question, "Has my camera been.........probed?" nag at your mind?