Mondegreen-the mishearing or misinterpretation of a phrase, typically a standardized phrase such as a line in a poem or a lyric in a song, due to near homophony.
Eggcorn-an idiosyncratic substitution of a word or phrase for a word or words that sound similar or identical in the speaker's dialect. Characteristic of the eggcorn is that the new phrase makes sense on some level ("old-timers' disease" for "Alzheimer's Disease").
Soramimi kashi-a word used in the Japanese subculture language to describe lyrics of a song that sound like the original in one language, but produce a different meaning when interpreted in another language.
Amphibology or amphiboly-is an ambiguous grammatical structure in a sentence. ("Teenagers shouldn't be allowed to drive. It's getting too dangerous on the streets" or "I once shot an elephant in my pajamas. How he got in my pajamas I'll never know.")
...all from wikipedia