I finally got around to seeing the highest grossing film of 1918 yesterday--Mickey, according the Wikipedia, made eight million worldwide. A simple story about a charming tomboy, who lives and works at a mine literally called "Tomboy Mine", who captures the eye of the wealthy owner of another mine. It's all just an excuse to watch Mabel Normand work.
She plays Mickey, the tomboy, who's a bit of a nuisance to her adoptive parents, constantly pulling pranks on her adoptive father like stealing his hat in the morning or playing with a cat in the mine shaft.
Normand unquestionably comes off as naughtier than her contemporary and friend Mary Pickford. She's very natural and quick with her sidelong glances and sly grins. The movie has a plot about her inheritance (the gold mine) and two handsome and wealthy gentlemen vying for her love, but she doesn't seem to care about any of these things as much as she cares about jumping around and spinning.
But you don't have to take my word for it. The whole public domain extravaganza is online for free on YouTube.