The words lo-cal, locale sound the same but have different meanings and spellings. Why do lo-cal, locale sound the same even though they are completely different words?
The answer is simple: lo-cal, locale are homophones of the English language.
(of food or drink) That contains fewer calories than normal
A place, especially with reference to a particular event: the locale of a crime.
The scene or setting, as of a novel.
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.