Two days before she’s likely to trot at least once onto the Staples Center stage to pick up at least one of the top-tier Grammys she’s been nominated for, R&B wailer Mary J Blige will be guest-starred on an episode of The Ghost Whisperer, playing a coach in a storyline concerning ectoplasmic goings-on in high school cheerleading.The show airs tomorrow, the Grammys on Sunday. (Photo: Ron Jaffe/CBS)