“Quiet on Set: The Dark Side of Kids TV” exposes the alleged toxic environment child actors endured at Nickelodeon in the late ’90s and early 2000s — but Marc Summers didn’t know that when he agreed to an interview. The famed network host — who famously led “Double Dare” and “What Would You Do?” — revealed that he felt entrapped by the documentary’s producers when he appeared on the series.“They ambushed me,” the 72-year-old said on Friday’s edition of z100’s Elvis Duran and the Morning Show.