A school in northern Malaysia has been evacuated due to an outbreak of ‘mass hysteria’ when pupils were ‘possessed’ by a spirit , local media has reported.The building was shut after students and teachers claimed they saw ‘ghosts’ walking the halls.School authorities alerted Islamic traditional experts, scholars and even witch doctors to perform prayer sessions and ‘exorcisms’ inside.The hysteria began last week after a number of people claimed they had suffered supernatural experience.They have now reopened the school but officials are still trying to figure out what happened.