A 30-year-old woman was struck by a stray bullet that came flying through the ceiling of her Brooklyn apartment, cops said Monday.

The bullet was fired from upstairs apartment 2B down into 1B at 203 Underhill Avenue in Prospect Heights just after 1 a.m., according to police.

One neighbor, who declined to give her name, told the Post there were people arguing in apartment 2B early this morning.

“I was awakened by noise I heard. I heard a noise and people arguing. I didn’t know somebody was shot until reporters came knocking on my door this morning,” said the neighbor.

“I don’t know the people who live there. It’s an older man in his 60s,” she added.

The victim was struck in the leg and taken to Methodist Hospital. She is expected to survive.

Two men were taken into custody for questioning but it was unclear if either were the gunman, cops said.

Two NYPD officers were stationed outside the apartment on Monday afternoon.