Monster Comes out of TV and Eats Grandfather

by Lee
(Montana, USA)

If this rings a bell, I'd love to know the name of this 80's flick. I've seen parts of it on late night TV over the last 15 years and I can't find it anywhere.

Plot: grandfather and grandson are home alone one night watching movies on TV. An alien/monster comes out of TV and takes over house. I think the grandfather gets eaten at one point? Thanks!