The one most often used in error, usually as a substitute for one of the other two, seems to be site. Cite means to be called to appear, as in court, or to quote as an example or proof.
Site is a location or scene of something or, as a verb, to place something in a location.
Sight of course refers to seeing or the sense of sight. Misplaced modifiers are confusing, usually because the modifier is too far away from the word or element it is supposed to be modifying. A modifier is said to be squinting because it looks both ways in a sentence. It is located between two elements, and the reader has to decide which one it modifies. Some say it should never be used, others that it should always be used.