It might also help just to swap sides. If the light is on the left and the computer is on the right, just swap sides. The computer's sensor could be on the same side of the unit that the light is on. Simply putting the light on the other side, an inch and a half further from the computer's sensor, could solve it.

(But the Faraday cage idea was more fun in a nerdy way. I like to take a "Damn you, physics! I'll put my stuff where I want to!" approach to life.)