Provincial police say a young person has been arrested in connection with an alleged threat directed toward a school in Caledon.Officers with the Caledon Detachment of the Ontario Provincial Police were called to Mayfield Secondary School on Mayfield Road near Bramalea Road around 7 a.m. on Tuesday.Mayfield Secondary School and James Grieve Public School were placed into a hold and secure as a precaution while police conducted their investigation. The hold and secure has since been lifted.Police say they determined the source of the threat but didn’t elaborate on the details of the threat.The identity of the youth arrested has not been released under the provisions of the Youth Criminal Justice Act.