How do I trace private numbers that call my house phone?

NO!
There is nothing you can do to trace private numbers.


However, there are a few things you can do:

You can call your phone company and have private numbers blocked. They can give the caller the option of pressing a button (usually 0/#) to unblock their number for that call, or call back using *82 to unblock their number.

You can try dialing *69 after they call to immediately call back the number who called you.

You can pick up the phone and say "Who is this?"


PS: You don't need to wait for any more answers. Simply scroll down to the "similar threads" to see 5 more threads confirming that there is no way to automatically unblock private numbers.