Cue creepy music, etc.
Actually maybe this is a better case for the FBI Behavioral Analysis Unit. I know there was no murder/serial killer but the psychology of behavior is how we're going to solve this mystery.
Let's go over the details of the case. No sign of forced entry, nothing stolen, no other part of the house was cleaned. Possible suspects include:
Unsub #1 - Miss Lola - Too much of a Diva for housework plus no opposable thumbs.
Unsub #2 - Professor Cody Baloney - Would totally love to vacuum the house if he could but again, no opposable thumbs.
Professor Cody Baloney at your service.
Unsub #3 - Strummerpants - Normally would be Prime Suspect #1 but has a rock solid alibi since he was with me the whole time.
I'm pretty sure I'm innocent.
Unsub #4 - Vacuum Fairy - If only . . .
Unsub #5 - Aliens coming to earth to play practical jokes on unsuspecting earthlings
(Aside - I find it hilarious that if you google 'aliens smirking photos' you get a photo of Dick Cheney. I'm not even kidding, try it for yourself).
Sadly the aliens option is looking like the best possibility at this point. Unless of course someone finally invented time travel in the future and my future self came back to mess with me. I could totally see myself doing that to myself.
But wait, Special Agent Garcia is hot on the case.
She tells me to go in the garage and check the windows and sure enough as soon as I look in my garage and see that one of the windows is no longer broken I crack the case.
Garcia hacks into Jonny's email and finds out that he's made a 9:00 appointment with a window guy to repair one of the garage windows that was damaged in one of our zillions of wind storms this past winter. Now why has he taken it upon himself to vacuum in this short window of time that he's home while the window guy is here?
Unsub #3 - I knew he was somehow responsible.
Wait, I thought I was innocent.
Strummer attacks the vacuum which makes vacuuming super fun so Jonny has taken advantage of his absence to run the vacuum in peace. Case closed.