Help Covid question

Am I suppose to get in contact with someone if I was just in the store and saw a man without a mask on who has a child in their house who currently has Covid? He’s been in close contact with the child the whole time- if so who do I get in contact with? It’s very concerning they’re going all over my town, not quarantined and WITHOUT a mask on. Okay so I’m going to add it’s a very small town and everyone knows everyone. Also don’t comment if you’re going to say “keep to yourself” not helpful at all sorry I’m taking the pandemic seriously unlike you?? There’s zero reason the man should be out let alone out without a mask on.