I know you can use retuner for autonomy, and I want to have more traditional ghosts, so I want to block them from autonomously doing things that you'd need to physically move the object to do, like, using the fridge or reading books

ITUN do have an OccultRestriction node, but I can't actually find an example of any interaction that uses it in order to know what values it can use. When EA does the reverse (allow an interaction for only an occult) they just use a requirement for the hidden trait instead.

Aside from just checking if the option gives you a list of occults to choose from, it would help if anyone can recall an existing interaction that certain occults don't have access to so that we can look at the ITUN.
It would also be a hard block, not just for autonomy.

Are you taking about real dead sim ghosts spawning from graves or playable ghosts?

Both, I guess?

playable ghosts are real sims, supernaturalws, like witches, fairy or vampires. So they behave like sims and only have some special animations and overlays. And an itun too.
Dead sim ghosts haunt and only appear during a special time (which is tunable via Retuner, also amount of ghosts), if the grave is put outside on the ground. I don't know if their interactions can be reduced.
I will have a look.

Can you specify what you mean with traditional ghosts?

Unplayable ghosts and playable ghosts are still considered to be the Ghost occult type, even if they function differently. They would both be affected by restrictions imposed on that occult status.

Luckily for us, I found that SimsMX already decoded what flags the OccultRestriction node can use.
The bad news is that it doesn't seem to appear in Retuner.

<Occult OccultRestrictionType="Ignore" OccultTypes="0x0" OccultTypesHumanAllowed="True" /> is a string that can be used in ITUN, within the <BaseAvailability></BaseAvailability> tag.
Setting OccultRestrictionType to Exclusive allows you to set a blacklist in OccultTypes.
The hex value for Ghost is 0x080.

In short, the answer is no- Retuner can't do this. But it IS possible, if you make your own tuning mod.