Jake Paul is going to have to take a break from boxing soon to do some serious unboxing ... 'cause TMZ Sports has confirmed the fighter just bought a mega mansion in Puerto Rico -- off of ex-MLB star Yadier Molina!!!
The Problem Child, according to a rep for The Caribbean Realty Group, scored the San Juan-area palace on Wednesday for $15,750,000 ... and it's insane.
The two-story property has eight bedrooms, eight full bathrooms, two 1/2 bathrooms, a fitness center ... and a luxury pool.
It's also got an elevator, a wet bar, a dry bar, a 6-car garage .