send a certified letter to them.

Sorry, I understood it was mis-delivered.
My bad.

I get wrong mail for people all over my neighborhood and from several blocks away and who never lived here at all.

This seems really simple to me.

You need to let PO know and see what they say.
The lady you were sending the quilt to needs to put on her 'big girl panties' go knock on their door and ask about it. She needs to take a pic of it with her. Explain the address error. If they refuse to give it back, tell them she knows they received it and that the postman delivered it to them and she is notifying the PO and filing a police report with the Police Dept. for theft of stolen goods. Also, let them know it is a federal offense to keep mail not belonging to them and she will file that too.
If they choose to give it back, all is forgotten.
If not, follow through.

Another good reason to have Delivery Confirmation with a signature (whatever it is called).

Sara should ask her neighbor about the package. In the meantime, will pray they do the right thing.

I was expecting a pkg a while back which didn't come as expected. Called UPS to track and it was delivered to my neighbor (who was not home at the time it was delivered) so UPS man put the pkg in a car parked in their driveway! They didn't use the car. But UPS told us and we went and found my pkg in the old car. God cares about what we care about. I will also pray that the quilt is found.

Okay my friends!!! Look what turned up on granddaughter's doorstep tonite??? Who cares how it got there!! I love this photo!!! Sara spotted fabric from last years birthday jacket and she said it was her favorite part of the quilt!! Thanks for all your prayers and suggestions. You're a wonderful bunch!

SEE WHAT THE POWER OF OUR UNITED WISHING AND PRAYING CAN DO!!
I know we willed that quilt to "come home" and by golly there it is.
I am so very pleased indeed.

Give God the glory! Praise the Lord!

That's wonderful!! And, it's a beautiful quilt!

YIPPEEEEEEEEEEEEEEEEEEEEEEEEEEEE!!! :D:D:D:D