I figured that it had been there all along, but I'm losing my mind and just didn't see it there.

Mr. Troutbend is working on a leaky roof in one of our storage buildings and I noticed he had a spray bottle of water there on a shelf. I hadn't seen him getting out the bleach to make bleach water to spray on any mold he might come across, so I was going to fill my ironing spray bottle with bleach water and take over there, but when I got to my ironing board, it was gone.
Mystery solved: he has been borrowing my spray bottle so I wasn't losing my mind after all. What a relief. Now I can worry about something else.