noun
extremely popular long-running TV show
Refers to a TV program that has achieved exceptionally high ratings and longevity, often becoming a cultural phenomenon. The term お化け (ghost/monster) here metaphorically suggests something extraordinary or monstrous in scale.
あのドラマはお化け番組と呼ばれるほど視聴率が高かった。
That drama had such high ratings that it was called a monster hit show.
このバラエティはもう20年も続くお化け番組だ。
This variety show is a long-running monster hit that has been on the air for 20 years.
Compound of お化け (ghost, monster, something extraordinary) and 番組 (program). The use of お化け metaphorically indicates something monstrously large or phenomenal, referring to the show's outsized ratings and longevity.