The words misses, missus, Mrs. sound the same but have different meanings and spellings. Why do misses, missus, Mrs. sound the same even though they are completely different words?
The answer is simple: misses, missus, Mrs. are homophones of the English language.
Plural form of miss.
Alternative spelling of missus. (Mrs)
Third-person singular simple present indicative form of miss.
Variant of missis.
Used as a courtesy title for a married or widowed woman before the surname or full name of her husband: Mrs. Doe; Mrs. John Doe.
Used as a courtesy title for a married, widowed, or divorced woman before her own surname or full name: Mrs. Doe; Mrs. Jane Doe. See Usage Note at Ms.
Used in informal titles for a married woman to indicate the epitomizing of an attribute or activity: Mrs. Wonderful; Mrs. Organization.
Definitions from Wiktionary, Creative Commons Attribution/Share-Alike License, from The American Heritage® Dictionary of the English Language, 4th Edition and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.
If they are spelled the same then they are also homographs (and homonyms); if they are spelled differently then they are also heterographs (literally "different writing").