Friday-night viewers are fickle, fleeting and few. So it seems the networks have decided to punish them with some new shows that are dreadful in their own ghastly fashion.

Just saying “Ghost Whisperer” (7 p.m., CBS) makes me laugh. And the title is only slightly more ridiculous than the show. Melinda Gordon (Jennifer Love Hewitt) has a special gift: She sees dead people. Or, more to the point, they see her. They seek her out in order to set things right with the living, or settle accounts on the spectral abacus, before “crossing over” or “going into the light” or some other spiritual jargon bandied about here with great authority.

Melinda sees ghosts everywhere. Her husband’s (David Conrad) dead brother shows up at her wedding, and for most of this debut episode, the unsettled soul of a Vietnam War casualty keeps breaking into the ramshackle home Melinda shares with her understanding hubby.

Shamelessly mawkish, the spiritual heft of “Whisperer” is undercut by Hewitt’s irrepressible glamour. She’s frequently haunted in her sleep. That gives us ample opportunity to ogle her in her low-cut nightgowns.

¢ By my unscientific count, “Killer Instinct” (8 p.m., Fox) becomes the 497th drama about an elite police squad on the trail of serial killers. It’s the 281st police drama with a principal character slightly messed up by the death of a former partner, and the 77th to team up a handsome loner (Johnny Messner) with a fetching female partner (Kristen Lehman). And, by rights, it should be the first show canceled this season.

¢ Set in a fertility clinic, the new drama-comedy “Inconceivable” (9 p.m., NBC) has a bad pun in its title. It also has a shot of a swimming sperm in its credits sequence, and it’s all down hill from there.

Tonight’s other highlights

¢ Scheduled on “Dateline” (7 p.m., NBC): an interview with Eva Longoria.

¢ Surprising news from Chicago on the hour-long season premiere of “Bernie Mac” (7 p.m., Fox).

¢ A murder may be part of a greater conspiracy on “Threshold” (8 p.m., CBS).

¢ “Viva Baseball” (8 p.m., Spike) salutes the decades-long influence of Latin American players in major league baseball.

¢ A judge’s wife is targeted on the season premiere of “Numb3rs” (9 p.m., CBS).

¢ Scheduled on “20/20” (9 p.m., ABC): greed.