Chances are VERY VERY low. How many words do we have? More than 150,000? What are the chances that someone would actually land upon a wallet with the same words as you have? You have 12 words, if only 1 word out of those 12 is different, it would already be a different wallet. Not to mention the order of the words. etc. If 12 words wasn't safe enough the devs wouldn't have chose it.
im not talking about the chance they land on my wallet.
Its about they landing on any wallet. Out of the billions out there.