Taylor Swift Alleged Trespasser Arrested at Her New York City Apartment

Taylor Swift's swanky New York City apartment building had an unwanted visitor Friday -- cops arrested a guy who'd traveled from out of town, desperately trying to find her.

Law enforcement sources tell TMZ ... Patrick Nissen, a 28-year-old from Nebraska, was busted in the vestibule of Taylor's Tribeca apartment building and he's been charged with second-degree criminal trespassing, a misdemeanor.

Law enforcement sources tell us Taylor was not home at the time, and Nissen entered the building through an unlocked door. We're told a security officer in the building saw that Nissen didn't have permission to be in the complex and called 911. Nissen allegedly told cops he was in love with Taylor.

Cops say other men have tried to see Taylor at her Tribeca apartment, and this guy has pics of her on his Instagram page.

Our sources tell us Taylor was NOT home at the time and the guy took a bus from out of state to get to the Big Apple.

Taylor's properties are magnets for these kinds of incidents ... several men have been arrested outside her homes in Manhattan, Rhode Island and Beverly Hills.