Actions for things that aren't present

Is there a way to make an action apply to something that isn’t present?

(I want a “switch” rule for changing characters, but it would be nice if you didn’t have to hunt down the other character first.)

Yes, for example:

Switching to is an action applying to one visible thing. [the word "visible" is essential even though it looks like it's the opposite of what it's supposed to do] Understand "switch to [any person]" as switching to.
(see also manual ch. 16.7.)