How do I get them stop calling?

What company is calling you? Credit companies are legally allowed to make calls for recovering their debts. You can't stop them legally. But the collection agencies are legally bound to stop the calls after sending a cease and desist letter.

But are they legal to call a place where the particular debtor doesn't live??

You need to send a cease and desist letter detailing the facts of the situation - that the person they are seeking doesn't live at that address or phone number, and request that they stop calling.

You seem to be bothered by this. Not only would I tell the collection companies to cease calling your house because said family member does not live there, but I would also tell said family member to return the call. If you keep getting harassed, you can file a complaint.

Inform the family member that some company is looking for them and that they should get in touch with the company at the earliest. Tell your relative that they should also inform the company to have your name removed from their system.

if you have called id and dont know the number answer "dominos pizza with this be pick up or carry out " they will ask for you relative or who ever they are tring to find and say that person doesnt work there i have gotten several collection to stop calling cause of that or another good one is answer "your local county sheriff department"they usual doent say any thing and hang up and dont call back