The most common way is to use it is as a blanket term for everyone, but said while discussing an unknown past of someone known.. "Why do you think jerry is being so strange whenever we ask him about his collage years?" "I am not sure. Maybe he did not finish school." "That is not it. I know he graduated. I saw pictures.. I agree he is acting strange though. I wonder why. I guess Everyone has skeletons in their closet."

The businessman decided not to enter politics because he has too many skeletons in his closet. The press is always looking for skeletons in a celebrity's closet.

It is usually used in reference to some celebrity or well-known person. It is very seldom used concerning people we work with or acquaintances. "The politician resigned when it was found he had a skeleton in his closet - multiple convictions for drunk driving, some of which were recent." "He will be appointed commissioner by the mayor, following a background check for any skeletons in his closet." Quote from Burt Reynolds (famous actor): "I could never go into politics. I don't just have skeletons in my closet - I have bodies!"