Jennifer Love Hewitt's Ghost Whisperer attracted a series-high 12.6 million viewers Friday, but only 8.1 million of 'em stuck around at 9 pm for Threshold. That would explain CBS' decision to test out the freshman serial thriller on Tuesdays at 10 pm beginning Nov. 22. In turn, Close to Home, which currently occupies that slot, will shift to Fridays at 9 pm.