Few people who frequent occult studies discussion forums ever specify the spirit model that governs their thinking about what spirits are, how they come about, what they can and cannot do, etc. Often. a lot of that can be inferred from how people talk about their magic practices and experiences. From such inferences, several ideas seem to be fairly common across the breadth of the occult studies community.
1. There are different species of spirits, and within each species there are unique individuals (usually).
2. Many individual spirits (e.g. those with known names) have different/specific powers.
3. Spirits with known names and specific powers can be called forth by anyone who has the wherewithal, and if successful, will be the same spirit being, no matter who is calling, what millenium it is, etc.
3. Spirits [most] have abodes where they hang out, presumably doing spirit only stuff, when people aren't interacting with them to get information or aid from them.
4. Spirit abodes are often presumed to be extraterrestrial (not in the space aliens sense), extra-dimensional, or some such. A reasonably common idea is that the material world is like one side of a coin, where other side is a spirit world; or, that the material and spirit worlds coexist in the same space, but it takes some special procedure(s) for humans to gain access/awareness to the spirit world; sometimes the idea that spirit beings are pulled into the material at the magician's beck.
5. Spirits are either eternal or, at the very least are very long lasting (i.e. many thousands of human lifetimes).
6. Other ideas that are less common... just sayin'.
While a loose collection of ideas like that doesn't constitutes a comprehensive model, it's a start though. I submit that everyone who strives for intercourse with spirits does have a working spirit model, and I'll add that trying to specify it is a useful exercise.
Okay, so It's fair to say that my own spirit model doesn't comport well with many of the common ideas that circulate here abouts. That's probably one among several reasons why some of the things I like to talk about are difficult to understand, or easily dismissed: my ideas are often considerably outside the mainstream of the occult studies community.
I don't expect anyone to agree with what follows. I just want to put it out there for interested parties to consider. I'll lay out the spirit model that guides my thinking and practices, to the best of my knowledge at present, in another post. I welcome comments, questions, and especially criticism.