A mondegreen is the mishearing or misinterpretation of a phrase as a result of near-homophony, in a way that gives it a new meaning. It most commonly is applied to a line in a poem or a lyric in a song.
The unintentionally incorrect use of similar-sounding words or phrases in speaking is a malapropism. If there is a connection in meaning, it can be called an eggcorn. If a person stubbornly sticks to a mispronunciation after being corrected, that person has committed a mumpsimus
Examples include, “Gladly, the cross-eyed bear” (from the line in the hymn “Keep Thou My Way” by Fanny Crosby and Theodore E. Perkins, “Kept by Thy tender care, gladly the cross I’ll bear”). Carroll and many others quote it as “Gladly the cross I’d bear.
There’s a bathroom on the right (the line at the end of each verse of “Bad Moon Rising” by Creedence Clearwater Revival: “There’s a bad moon on the rise”)
‘Scuse me while I kiss this guy (from a lyric in the song “Purple Haze,” by The Jimi Hendrix Experience: “‘Scuse me while I kiss the sky”).