Example:
Tell her and teller
Or cellar and sell her
Try homophone, defined by Merriam Webster as
A word (one of two or more) that is pronounced like another word but is different in meaning, origin, or spelling.
Full definition is
One of two or more words pronounced alike but different in meaning or derivation or spelling (as the words to, too, and two)
A character or group of characters pronounced the same as another character or group