Here's how I think it works. This is after a year of actively interacting, taking instruction from a medium (not through with this course yet), and regular focus exercises (some call it meditation) to get my vibes to the level where we can communicate.
This is just my opinion right now; it might change with more experience.
I think they are around all the time. I think they exist in the same space we do. It's a matter of being able to "tune" them in. They have to vibe at a lower level; we have to raise our vibration level. When you each do your part, you can get through.
Practice has a huge amount to do with how successful one can be.
Interestingly enough, one way to tune them in is through music. Once I asked what it was like "over there." The song "Dancing in the Moonlight" came through. When I listened to that, I understood a lot about what their existence is like. It's all good. it's mellow, it's laid back, it's fun.
They continue to work on projects that might even have applicability to what is going on here, such as environmental issues. Or something they were working on in their careers here.But their real thing (and yours, one soon finds out) is feeling emotions. This is a really hard lesson for cerebral types.
We have blinders on here. We only see about 90% of what there is. And feel. It is extremely intense and way, way over anything we experience here. Sometimes it will take me days to work through a concept. And feelings, just trying to get a grip on that can take a long time, a lot of thought, getting used to, working with, etc. Then there's verification, which you never know when or how you will get.
Animals have projects, too. About six-eight months after she crossed over, Chubby communicated to me what her project was. She was wildly enthusiastic about it. I was on a high for days, just from feeling her enthusiasm.
The feelings are almost all good. That alone is enough for me to want to continue with this endeavor. Everything is good, happy, funny. Oh yeah, they are really funny over there. What a great sense of humor and wit they have, and yes I am talking about the animals, too. Sometimes their wit has me laughing for days.
I could write for hours on this but I think you can get the idea from this. I might write more if some pertinent points come to mind. But to circle back to what you said, I believe they are right there with us, right now. It's just a matter of tuning them in, like how you tune in a radio.