Just as we learn that Ashton Kutcher is replacing Charlie Sheen on “Two and a Half Men,” we hear (ghost) whispers of another television switcheroo. Apparently, Mariska Hargitay, who plays detective Olivia Benson on “Law & Order: SVU,” has negotiated a new contract for the 13th season of the show. Mid-season, Benson will get a promotion to supervisor, meaning that Mariska will clock far fewer hours on the show. So who will be stepping in to be Elliot Stabler’s new partner? Jennifer Love Hewitt, apparently. The actress is in negotiations for the role, and sources say it looks like she will be signing on. After all, she did appear on the show earlier this year, playing a woman who was stalked by a man for 15 years in an episode that highlighted the problem of rape kits being backlogged at police precincts. So obviously, she is into the series and its ripped from the headlines approach. But I’m curious how the writers will make that work. I mean, how exactly would her character go from victim to detective in 12 months? Perhaps with a flash forward?