As Edwin Ashworth has already mentioned, your example are homophones, not homonyms. A homonym looks the same and sounds the same. Stalk (follow) and stalk (stem of a plant) are homonyms. Read (a book) and reed (plant) are homophones.
In the strictest sense, there is sometimes a distinction drawn between 'true' homonyms as above, and polysemes where the words have a shared etymology and are technically the same word with differing meanings, such as mole (furry thing in a hole) and mole (a spy).
Alternatives to mondegreens -
malapropism - (the unintentional misuse of a word by confusion with one that sounds similar
or eggcorn if the phrase retains an unintentional meaning, signaled out instead of singled out for example.