Actor Mark Ruffalo says his son 15-year-old son Keen thought his father was stuck inside the television.

Ruffalo says that Keen believed he was "literally" trapped inside the electrical appliance when he was two or three years old, reports people.com. 

“The first time he (Keen) ever saw me on TV, I was away and he was there with the nanny," Ruffalo said. 

"He saw me on TV and he ran to the TV and started banging on the side of it, like: 'How is he? Papa! Papa! Come out, come out'," he added. 

Ruffalo added that he found Keen's reaction endearing.

He said: "It was really sweet. It was so literal for him. He literally thought I was in the TV!"