Via @yueheng, I learned about The Great Vows of Ksitigarbha Bodhisattva blog. The most recent post talks about the condition of being pressed by ghosts in your sleep.

Ever experienced being pressed by ghosts in sleep? Common symptoms are:

you wake up in the middle of your sleep

you are stationary and however you struggle you cannot move

you may open your eyes and look around but you can’t turn your head/neck

you open your mouth to scream but no voice comes out

Ghosts were a core part of the Buddhist milieu I was raised in, but they’re something I spend very, very little time thinking about these days. I am little affiliated with either Mahaynist or Chinese Buddhist institutions, but I enjoy learning more about other traditions. I’m also keen on learning Chinese too.