This trap was created for Oswald McGullicuty, a reporter and sensationalist of the jigsaw cases. The rack that Oswald was strapped to was designed to bend his arms backwards, snapping them, followed by his back. The only way for Oswald to escape was if Tapp managed to connect three circuits in three electrical boxes. Tapp completed the task and freed Oswald, however, Oswald ran directly into another trap triggered by a tripwire, crushing him between two large metal plates.
Hello, Oswald. Your newspaper has been the primary source of information about my message, why I do what I do. But your motivations are selfish. You spread my message, but pervert it for your own personal glory. You twisted your words to implicate Detective Tapp, to make the public suspect him to be me, the device you are strapped to will twist until your body is broken. To stop the device you must complete the electrical circuit panel. If you do not complete the circuit in time, words will not be able to describe your agony.
Jigsaw explaining the game