Shia LaBeouf -- Calls 911 -- There's a Strange Chick "In My House!"

Shia LaBeouf called 911 after coming face-to-face with an intruder at his L.A. home ... and you hear Shia scream at the strange woman, "Don't touch me!."

LaBeouf -- who sounds relatively calm -- tells dispatchers a woman who'd been stalking him for weeks was right at his door.

Cops arrested 31-year-old Graciela Nahle. Law enforcement tells us ... she's been there twice ... both times skulking around.

Nahle copped a quick plea after last weeks' arrest .... no contest to trespassing. She was sentenced to 45 days in jail ... but she was out in just 4 days.

She's also been ordered to stay far away from LaBeouf.