I was thinkin' the same thing.  

2 days ago me and a technician re-worked a projector/screen installation.  We pulled a 35' extension cord out the wall.  It was running from the projector in the ceiling down the wall, behind the av equipment.  Oh yeah, it was also spliced and wire nutted (with foil tape) twice.  Yikes.

jokingly I looked at the homeowner and said...Go ahead and tahnk me.

For what?
Because I may have just saved your families life, and installed a sweet 110" screen on the same day.  :)

Don't put power cords in the walls folks.  It's really not worth it.Really.