Sophia Bush Alleged Stalker Arrested

Sophia Bush definitely had a scary situation brewing at home ... because a woman who kept allegedly showing up at her place just got busted for stalking.

Law enforcement sources tell TMZ ... a 36-year-old woman named Jhoseplyn Coreaarguello was arrested last week at the former 'One Tree Hill' star's Los Angeles area home, where cops say the woman kept coming by uninvited. She was leaving gifts and flowers addressed to Sophia.

She also followed Bush to other locations. We're told Coreaarguello was showing up at various restaurants where Sophia was dining.

What pushed things over the legal line ... sources with direct knowledge tell TMZ ... Coreaarguello was sending "aggressive Instagram messages."

We're told the Los Angeles City Attorney charged the woman with one count of misdemeanor stalking ... and she's facing up to one year in county jail if convicted.

The woman is still in custody on $50,000 bail ... and it's unclear when she will be released.