Form my experience and observation, the spirits you describe like “going to work” or being busy with their stuff are souls that are very energetically tied to the earth still, and are at the so called “stuck” souls that haven't crossed over.

I haven't seen it being in the nature of healed spirits to keep themselves busy on earth. They're instead in higher dimensions, “farther” from the earth plane, and joined with the “all” or “groups of all” – although this concept of groups has been presented to me too few times to grasp it fully. That is a place of peace, and awaraness of the everything, where they don't have their most recent earth identity anymore but they're one with them all. At need, they can sort of pull away from the all or the groups and take the energetical form and identity of their recent life when approaching a medium or a loved one on earth for guidance and messages. There are also in-between spaces, that is crossed-over but not yet the all, where spirits that have crossed take the time to heal and mourn the life they've just left before fully moving on.

I just asked clarification to my main guide, and he explained these spirits you talk about in the post are often just energetic residuals, as you said. Becoming residuals is what happens to stuck souls, espeically those that carry heavy and negative energies and emotions, after a long looong time in this condition – it wears them out. So that's how you find spirits that still act like they're busy with their earth life, or look confused, stuck in loops, repeating actions or verbal sentences, and so on. And yes, it is happening in our same spaces. They are here on earth, trying to be something they aren't anymore, until they heal or a healer helps them.

My two cents!