I don’t think it’s been done exactly that way, but there are humanoids that aren’t guaranteed anomalous. 4193 is almost non-anomalous, and doesn’t know they are anom. 4942 is a ritual (doable by non-anom people) that summons a non-anomalous entity. 4247 seems to have anomalous items, but was not anom until it tried to escape. 4306 it isn’t clear what is anomalous; apparently there is only an anomaly when you combine that human with those objects. 5996 we know what conditions make bad thing happen, but we don’t know the source.
How are you defining “normal human”? Authorial fiat is difficult to communicate. If someone “passes” anomaly detecting tests by coincidence, that would be indistinguishable from anomalous bad luck. And going that route invites the wrath of statistical math. Being the center of poltergeist activity without being attacked by it could still be some unconsciously reality bending. A normal human being watched by a higher power/strong reality bender that changes reality on the fly to make it look as though the human is anomalous, you would need a way to bring the entity into the story, otherwise it would just look like an anomalous human.
