In the end, they settled on the method most likely to work against ghosts: solar radiation interference, or simply, a UV lamp.
One trait of ghosts mentioned in the vast majority of horror movies was their fear of light. Most ghosts moved around at night. Weaker ones would vanish as soon as they came out during the day, while stronger ones would not be killed by sunlight after possessing someone, but still hated it. No matter how great their grudge, they had to wait until nightfall to take revenge.
The two Spider-Men worked together to make a UV lamp. Something like this was ridiculously simple for Spider-Man, so they had originally planned to make one at maximum power, but Helen stopped them.
Helen explained it this way: if the power was too high and the ultraviolet rays killed the ghosts directly, the zombie superheroes would regain their strongest weapon—their brains. Then they would start scheming to spread the zombie virus again.
So it had to injure without killing, merely making the ghosts uncomfortable enough to drive them away.
Spider-Man ran several tests. During that time, he even found a little ghost that had been teleported over and was wandering nearby to test it on. They settled on an intensity strong enough to affect the ghosts inhabiting the superheroes and built the device.
Then an astonishing sight appeared on the streets of New York: a group of people carrying a device like an oversized searchlight, chasing a group of strange superheroes with exposed gums at full speed.
The first one they found was still Captain America. At the time, he rammed straight through the Hudson River railing and fell into the water. The two Spider-Men carried the UV lamp and scorched him until he screamed repeatedly, causing him to flee desperately