Which episode of House is this? And which season?

A man lost one of his hands in an accident, but although his hand is gone, he still thinks it's there. The bad part is he 'sees' it to be in a closed fist position. As time passes he feels pain in the ghost hand, because the nails are growing deeper and deeper into his ghost palm. I don't know why he can't 'open' this ghost hand.

I was flipping through the channels of the tv when I came across the scene where House devices a plan for him to 'open' this ghost hand. He designed a box such that this man can place both his hands in the box but can only see his real hand. There is a mirror in the plane that divides the box for his hands, so, from the man's point of view, he 'has' two hands because he sees two hands- the real hand and its image in the mirror. House then tells him to close his real hand in a fist, so both his hands are closed and he sees both of them closed. House tells him to open both hands at the same time, and when he does, he sees the two hands opened, and is relieved of his pain.

I will give best answer to the first correct answer. Thanks!