Britney Spears is set to make a guest appearance in a US television sitcom. The troubled singer is "in talks" to appear in the primetime CBS show, How I Met Your Mother, sources have said. It is not clear what role Britney would play or when the episode would be broadcast. Although according to one US report, a source close to the series said it would be taped this week and would be broadcast on 24 March. The source also said that Spears will share scenes with the show's star, Josh Radnor, playing a woman who works in a doctor's office and who falls for him. Spears' last appearance in a primetime TV series was on the sitcom Will & Grace in 2006. Pictures by Splash News