A suspected intruder ran a secret meth lab out of Michigan State University’s largest academic building and was nabbed a day before final exams started.

Xin Tong, 31, was busted around 9:30 p.m. Sunday on the fifth floor of Wells Hall with several backpacks, duffle bags and a stash of chemicals used to make homemade methamphetamine, police said.

Campus police were responding to reports of a trespasser when Tong was caught. He mistakenly confirmed his identity when he offered officers an expired MSU student ID, according to an affidavit obtained by WILX.

Cops uncovered “several labeled and unlabeled containers of an unknown liquid substance inside” the bags, which they searched after obtaining a warrant, MSU Department of Police and Public Safety Chief Mike Yankowski said at a press conference.

Other unknown substances were scattered throughout the hall.

Police said that the various chemicals were identified as sodium hydroxide pellets, hydrochloric acid, methanol, isopropyl alcohol, acetone, and butane — all key ingredients for homemade meth that can be purchased legally.

The substances littered around the building also caused approximately $20,000 or more in damage between April 10 and April 26, according to the Ingham County Prosecutor’s Office.

Wells Hall was evacuated on Monday and closed through Friday “out of an abundance of caution,” according to a MSU news release.

The academic hall houses the school’s math, English, and all language departments. It is typically a crucial hub for students during the final exam period, which started on Monday.

Tong was charged with malicious destruction of property over $20,000 and operating or maintaining a methamphetamine lab on Wednesday.

Tong is being held at the Ingham County Jail on a staggering $500,000 bond. The Department of Homeland Security placed a hold on his bond, according to blocked Ingham County Jail Records viewed by The State News.

Police declined to identify Tong’s affiliation with MSU, if any.