Chambersburg Area Middle School North was placed under a shelter-in-place protocol Thursday morning while law enforcement searched the building.
School district police, Pennsylvania State Police and local law enforcement were involved in the investigation. All students were accounted for in their homerooms, and school officials reported there was no active threat.
The school said the building was being cleared as a precaution before the normal schedule resumed.
The eighth-grade school trip scheduled for Thursday was canceled.