Here's another story from same school I studied at in high school. This one happened to my best friend in our auditorium.
My best friend is a member of the Thespians Club. I'll call her Irene here. They held plays in our school auditorium every August, which is the month given to them by the school administration, to celebrate the founding of their organization. They also supervise any other skits or plays to be shown on stage for any other organization that's going to celebrate their week/month. She was the vice president of the Thespians Club, and officers of the club normally stay late in school to prepare for plays. This particular thing happened to her one late afternoon while preparing for a play to be shown by the Kung Fu Club.
Our auditorium has red curtains with wide stage. It's really beautiful but if you look backstage, it's a war. There are a lot of props and costumes left off by other organization's that performed plays and other shows. All the trash are left here in any case some other group might need such a prop or costume and they were really not kept that orderly even with much work from the Thespians Club.
Irene and the president of the club, which I would call Rachel, stayed late to prepare for the said play. They asked all the other members to go home due to the time. And since Irene's parents are abroad and Rachel only leaves a few blocks away, they can come home late unlike the other students.
Irene and Rachel worked on fixing the props and the set for the upcoming play when Rachel felt that the auditorium was so silent. So she went upstairs to the Audio Room and played some local music. She rested there for a few moments when the song "Beautiful Girl" played. It's a local song here in the Philippines sung by Jose Mari Chan.
While the song played, Rachel looked down to the stage and she saw a girl in the middle of the stage. Rachel got curious, as she knew that only she and Irene are the only ones left in the auditorium, so she thought this was one of the performers doing a last minute rehearsal. So she watched as the girl stood there, motioning everywhere, as if she was singing the song Rachel was playing. She was wearing a very long white and pale purple dress. Then a thought suddenly struck her. Why would this girl lip-sync to the song when the Kung Fu Club's play is about the history of the said Martial Art. Where would the song fit in the play?
Curious. She stopped the song midway. The girl suddenly stood still. Rachel never removed her eyes on the girl. Then the girl looked up to Rachel through the glass of the Audio Room. Though the girl is really pretty, Rachel noticed how sad and pale this girl looks like. The girl just continued staring at her and Rachel also kept on looking at her. Rachel did not notice for how long this lasted, when she suddenly noticed that Irene was dragging a wall partition for the set up directly right through the girl. Rachel shouted at Irene, and the latter looked up with confusion on her face. Rachel told Irene, "You're going to squish her!"
Irene looked around and asked who Rachel is referring to. When Rachel tried to point the girl, the girl is already gone. Rachel quickly went down to the stage and asked Irene if she saw the girl in a white and purple dress. Irene said no, said that they were the only ones left there as the janitors asked her to lock up the auditorium as they are going to clean the gym. Just to be safe, Rachel still asked Irene to help her to look for any possible student left and might be trapped in the auditorium but they found no one.
Irene and Rachel told us of this story right after the Kung Fu Club's presentation. One of our friends said that it might be a ghost but Rachel does not believe so. Well, we graduated never finding out about it either.