In a previous job, we used to joke about having a life sized cardboard cutout of the lead engineer left in the head end. Things would not be working "nominally" to the point we needed help. As soon as the engineer would walk in, the erratic behavior would stop. We joked that the equipment only behaved that way when he was not in the room. We wanted to test the theory to see if the equipment knew him or would be fooled by the cutout. You know, for science. Nobody was vested enough to actually pay to have it done though.