UV light Sterilizer caution

I’ve bought several uv sterilizers off eBay and Amazon for hearing aids.

I confirmed with a uv light card test, none of them emmitted any uv light.

Just a public service announcement to validate your sterilizer when you get it and confirm it works or return it

Hi, what is a " uv light card test"? How can we do it?

Buy them on Amazon, they are like 5 dollars and resusable