Answer: Mike and his wife, our old neighbors in Florida, bought a sailboat at auction, and they plan to live on it over the summer.
Explanation:
✗ Mike and his wife our old neighbors in Florida bought a sailboat, at auction, and they plan to live on it over the summer.
➜ With an appositive, it should be "Mike and his wife, our old neighbors in Florida, bought...", we are missing commas here.
✗ Mike and his wife, our old neighbors in Florida, bought a sailboat at auction and they plan to live on it over the summer.
➜ We have two independent clauses here, so we need a comma between "action" and "and".
✓ Mike and his wife, our old neighbors in Florida, bought a sailboat at auction, and they plan to live on it over the summer.
➜ This is correct.
✗ Mike and his wife our old neighbors in Florida bought a sailboat at auction and they plan to live on it over the summer.
➜ With an appositive, it should be "Mike and his wife, our old neighbors in Florida, bought...", we are missing commas here.
The sentence with the proper comma placement is:
"Mike and his wife, our old neighbors in Florida, bought a sailboat at auction, and they plan to live on it over the summer.
"This version correctly uses commas to set off the nonessential clause "our old neighbors in Florida" and to separate the two independent clauses joined by "and."