My Note on the Neighbor's Door

Dear Neighbor in Apartment 206:

Welcome home. We are giving you two, brand new, 9-volt batteries. It is our hope that you will replace the battery currently in your smoke alarm with one of them, and then use the second in six months when it needs maintenance again. You may not be aware, but your smoke alarm started beeping at 7am on Wednesday and continues as I write this.

We hope you were able to relax during your vacation. We know how hard it is to sleep in a noisy environment.

Sincerely,
Your second floor neighbors.