Ok there's a horror film I remember watching when I was younger and can't for the life of me remember what it is! All I can remember is at the very end there being a woman and one or two kids in an old house using the stove for light after the electricity goes out to save themselves from being killed by whatever creature/demon that was after them because it couldn't show itself in the light. Only disguise itself as children saying "turn off the light".

(When would this be, 1980's, 2000's? ) Sounds like it might (might) be Don't Be Afraid of the Dark (there are two versions)
...Sally finds that evil little creatures that fear the light have escaped from the underground through the ash pit and are threatening her...
Don't Be Afraid of the Dark (TV Movie 1973) - IMDb (http://www.imdb.com/title/tt0069992/)
Don't Be Afraid of the Dark (2010) - IMDb (http://www.imdb.com/title/tt1270761/)