Mel B claims the house she used to live in has become a modern-day "Animal House" ... so she's snatching back possession of it from Stephen Belafonte.
Mel says she'd given her ex-husband access to their former family home in the Hollywood Hills so he could prepare it for sale. It's been listed for more than a month, but in docs ... Mel says she caught wind through social media that Stephen was throwing some killer parties there.
Mel says she found out about the ragers and went over to the house on May 25 to get her remaining Spice Girls memorabilia because she was afraid it would get trashed. According to the docs, things got contentious between the exes, and Mel opted to call cops. She says Stephen refused to leave the home, and officers put him in handcuffs.
Mel says Stephen's attorney showed up, and shortly thereafter cops released him.
In the aftermath, Mel says she inspected the home and found broken locks, and several pricey items were missing ... including a $10,000 Baccarat chandelier, and a one-of-a-kind Marilyn Monroe painting.
The judge has now given Mel sole use and possession of the home until a hearing next week.