If you fall far enough back down the scale of 'bundle theories', you are reduced to a place where existence is, in fact, not only a property, but an accident. Philosophically, we do not like this notion, but it has become inescapable.
Both in quantum physics, and in many psychodynamic theories in psychology, only the 'tendency to exist' can actually exist. (And I will not play the word game about whether the tendency then exists or only tends to exist. We are already well beyond the point where language will help make any of this clearer.)
The probability of a particle being in a location can only be determined when another particle interacts with it. You need two complex vectors to have a positive dot-product. Otherwise the particle may, in fact, never need to exist, in order to have its effects on the universe. It might only increase the odds of other particles existing, or influence them to be in a slightly different location.
Physics, forced into this corner, does fall back on the wave equation, which makes intuitive sense only if you adopt a notion like the tendency toward existence as a pervasive substance. The probabilities accumulate as complex potentials, so in the absence of true existence, the particles can still accumulate and have influence, as a field effect might, which is basically an immaterial substance. We can get patterns of interference that create multiple photons at once, quite close together, even though until they had a reason to interact, they did not actually exist as photons, but only as potential photons.
At the same time, object-relational entities that are based in intersubjective communication can only 'tend to be' part of a person's thinking or motivation. You need aspects of the environment to draw them out, and they may lie dormant forever, and only be expressed by other bearers of the same complexes. That does not mean their presence in one individual who does not communicate them is irrelevant to the person who does. Like the particle, the odds accumulate even when they don't exist, and when precipitated, will be composite.
The panic in a crowd may be precipitated by one individual's action, but is already incipient in the crowd itself, and might not have come to the point of precipitation if the set of individuals present were not the same, or did not at least contain tendencies toward the same fears.
Of course, this is not the level of reality where most of us dwell mentally, so the billion-to-one chance that existence actually acts like an accident is not worthy of ordinary consideration. But in an absolute sense, we can no longer deny that this is the case.
Of course, strictly taken , examples do not answer your question. But I would contend that this model of a subtle substance correlating to the tendency to exist is not too accidental, and that we are driven to it by the structure of our inquiry.