Two kinds. The kind where you're not sure what's out there, so you act as if there's nothing. The kind where you're not sure what's out there, so you act as if there's something.
The first is exactly what its reputation and stereotype say it is. An atheist who is squirmy about it. It's someone who doesn't respect your beliefs but wants to pretend they do. "I think I see nothing, but I'm not going to say so."
The second is humility. After all, it's not hard to come up with folk who thought they saw something and were obviously wrong. Do you have some decisive advantage? Might you not also be wrong? "I think I see something, but I'm not sure what it is or what I should do about it. Nevertheless, I'm going to take a guess." Humility with initiative.