People misspeak all the time, but usually, the unintentional words that come out of their mouths aren’t synonyms for the term they’re trying actually say. For example, if you’re trying shut down the obnoxious couple sitting two rows in front who’ve been making out all game with the line “Get a room!”, and for some reason the words “Get a tomb!” comes out of your mouth, welp, that’s an accident. But if you say “Get a enclosed sleeping facility!”, it’s pretty obvious you’re not particularly familiar with the idiom. Also, it means you do not have any friends and might have some bodies in your crawl space.