Spooky Birthday surprise!
I'll go into this at greater length at a later date, however long story short, back in the 90s I took an 8mm cine film camera to a party, loaded with B/W grainy film stock. We filmed a bit of the party aftermath and made an animation. I got it developed but my projector broke so we never looked at it properly since, but would talk about it occasionally.
As a surprise for my birthday Mrs B got it digitised. We just played it and this figure briefly appeared on the screen. We have no idea who this was but it looks like a little girl. There were no children at this party and we can't imagine where this has come from.
Haunted party