When Steven Greenstreet visited Skinwalker Ranch in the summer of 2022, he asked to see their best evidence of anomalous events. One of the things they showed him was the above video.
It shows the interior of the abandoned Carriage House. The camera is facing the sun, which streams in through the open door, an upper opening, and numerous gaps in the roof. There are four rafters visible, which I'll refer to starting with the one closest to the camera as the "first rafter".
We see two luminous objects on the right, they are the same bright white as the sky
The objects seem to dance around randomly. A bird flies from the chimney to the fourth rafter back, at this point the upper of the two objects (and presumably both of them) is in front of the 2nd rafter
The objects waft around, they move right and fade out, then the bird flies away.
Greenstreet suggested they might be small caterpillars, like this:
That's possible, but to me their motion and the way they fade out at the end suggests a "silk in sunbeam" explanation. I think the unusual light condition mean that a beam of sunlight is strongly backlighting two silk threads fairly close to the camera.
Here's an example of silk in sunlight, not backlit, just in a (fairly wide) beam of sunlight.
I don't think they are particularly out of focus, just very bright, and hence our old friend glare shows up.
It's raining here for the foreseeable future, so I did an indoor experiment with a simulated sunbeam.
And here's a closer versions:
We see at the correct angle we can get a super bright segment of the fishing line, when the exposure is set to show the interior.
This is just using a flashlight, about 15 feet away, through a slit in a cardboard box. I suspect a sunbeam would be considerably brighter.