The words whish, wish sound the same but have different meanings and spellings. Why do whish, wish sound the same even though they are completely different words?
The answer is simple: whish, wish are homophones of the English language.
Alternative spelling of whisht.
A sibilant sound, especially that of rapid movement through the air.
To make such a sound.
Something desired or longed for.
A desire, longing, or strong inclination for a specific thing.
An expression of a desire, longing, or strong inclination; a petition.
To long for; want. See Synonyms at desire.
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.