For decades, unbeknownst to the public, a number of supranormal and unusual threats had threatened humanity from the shadows; taking many forms. Aliens, mad scientists, caped criminals; it presented a real threat to the world, and had been thought too likely to cause panic to risk these unknown problems becoming public knowledge.
The governments of the world did discover a solution: Hedgemann's Serum. A vial of miraculous fluid that could potentially give a human being superpowers. The problem was, the formula was very unstable and reacted highly adversely to foreign DNA, namely, the 99.99% of humanity which weren't a perfect match for it. Some test subjects suffered truly horrible fates. Some became entities of incredible might. Often it lay in between. And so the Serum could not be used on reliable field agents already trained: it had to be used on unsuspecting nobodies.
Over the decades, access to medical records and knowledge of genetic sequencing made it easier to find individuals likely to have a positive reaction to Hedgemann's Serum. And modern pharmacology provided ways to begin moulding these random civilians into ideal agents. Fortunately; it was less risky to be seen so publicly nowadays, the world used to superhero media and so it deemed safer to slowly let some of the agencies' activities become public knowledge.
But still. It was dirty work producing superheroes, and so adverts were surreptitiously placed where suitable candidates would see them, often to try and coax them into coming in for some anonymous job. Such was the best possible way to keep a stream of recruits for the Co-Operative Agency for Paranormal Entities: CAPE.