Sanaa Lathan has a stalker

"Love & Basketball" star Sanaa Lathan is being stalked by a man claiming to be her husband ... who was discovered sleeping in her home ... law enforcement sources tell.

Lathan just got a restraining order against 28-year-old Shawn Caples, who was discovered dead asleep in her laundry room last Friday by contractors. 

The man -- who insisted he was Lathan's hubby -- was shooed away ... but she says he reappeared later that day.  Lathan screamed at him to "get the f*** out of here" and then called the cops when he refused to leave.

In her docs, Lathan says Caples showed up at her doorstep 3 days later ... and she hid in fear.

Caples is now behind bars after being arrested for stalking.  He's been ordered to stay at least 100 yards away from Lathan once he's released.