Experience. In order to assess the risks, you need to have a good understanding of the object with which these risks are associated. The better you understand it, the more accurately you can determine the risk, in fact, you reduce the likelihood of a singularity (for example, you exclude the chance that this something may be more dangerous than you think now and will ultimately lead to your death, even if you avoid it all your life).
But in the process of studying, your attitude towards the object may change, because you are studying something about which you do not have a complete understanding, which means that you may be mistaken in its essence, and something frightening may turn out to be something then very enjoyable. This process is sublimated into subjective experience. For example, you may consider that a certain group of food products is poisonous, and having tried one of the products of this group under some circumstances, you will understand that this is not so, or so, but not fully (not very poisonous, for example). Perhaps you decide that all products of this type are harmless, or perhaps only the type you tested. Depending on the configuration of your perception and the product in question, you can stop there, or continue to try other products of this type, perhaps because they are tasty or to clarify your risks.
When is what something seems both interesting and repulsive - you are interested in trying a new product, but you are afraid of poisoning, but not enough to stop thinking about its attractiveness and weighing the risks.
So by definition. "Scary / creepy / unpleasant" means that the person is NOT ATHLETE to this.
That is, he reacts emotionally, it is not indifferent for him, for him there is energy in the subject.
This is the same kind, as hatred is not the opposite of love, the opposite of love is indifference, indifference)
And if you are not indifferent, this is, by definition, an attraction of attention.
At least because you want the frightening as- then to control, even if it is illusory, - and to control means, to know, to be aware.
True, indeed, things that are fundamentally terrible for him, a person often, on the contrary, displaces them from consciousness and defends themselves in different ways , - but this is already a topic of psychological protection.
Perverts love it, and others learn scary, creepy, unpleasant, repulsive things to shield themselves and others from this all in the future.