From much practice, master conjurers know the difference between Dark, White, and Black energies. While conjuring, they can distinguish the energy differences between Vampires from Angels in a split-second and take appropriate measures. However, this rarely occurs because when properly written, invocations conjure only the intended target and nothing else.
This is one of many reasons why it is imperative to work with experienced, trusted, and respected conjurers only. Working with anyone less presents vulnerabilities which often lead to negative consequences. Venues like eBay and Etsy are rife with unscrupulous charlatans and inexperienced wannabes. Most of these sellers do not disclose crucial details such as where they learned, how much experience they have, or what their ideology and methodology is.
With the practice of Spirit Keeping, nefarious unbound spirits do not hijack bindings, or sneak through conjurations to replace the conjured spirit, especially when you are working with an experienced conjurer. There isn’t any reason for an unbound spirit to do so. In fact, that would directly contradict their goal. Any unbound spirit can encounter any person on Earth, at any time. They do not need a conjuration, let alone a binding, to come to a person or into their home. For a prankster or troublesome unbound, they do not want the respectful covenants of Spirit Keeping that a binding brings. That would be counteractive to their troublesome nature. If someone tells you that a spirit has hijacked a proper Spirit Keeping binding, or snuck through instead of the proper spirit to be conjured, you need to immediately distance yourself from the person telling you that you have a hijacking spirit – especially if they are requesting money to correct the binding.
In summary, trusted master conjurers will not conjure or bind the wrong spirits.