Kinetic Games has teased a couple of the new items coming in Phasmophobia's Christmas update. Peeping the game's Trello board, there's an entry for the "Christmas [REDACTED] Update" that was originally created earlier this month (thanks, PCGamesN). It's since been updated to show two new cursed possessions coming with the update: a summoning circle and a new variant on the voodoo doll.
It's unknown exactly how the two items will play into your ghost-hunting adventures yet, though there's a good chance the summoning circle will let you spawn the ghost wherever you throw it down. There are two more cursed possessions landing with the update, but those are still being kept under wraps. More Ouija board questions will be added too, alongside some other unknown features.
There's no release date on the Christmas update, but going by name you'd expect it soonish. Kinectic Games has done a fairly decent job of dressing up Phasmophobia with some consistent updates throughout 2021, even if it is still a bit of a janky mess at times. The Nightmare update released last month added a ton of new stuff, including the game's first outdoor map, and a bundle of new ghostly baddies.