What one item would you put in a time capsule to totally confuse the person who opens it? Assume the capsule would not be opened for at least 25,000 years. Preferably, it would be a stand alone product of some sort (not a part of an item).
A pet rock
a voting card
A replica of an Edina (Early Native American) pot made by my best friend using what’s believed the same techniques, including firing, that they did. Of course, said best friend is an archaeologist, so she may not go along with this. Then again, knowing her she probably would! 
CJ
There’s always my renfaire get up.
Or a collection of painted rocks Lady Chance is working on. She’s in a primitive mode having been inspired by some old cave paintings she’s seen on some TV show.
A John Holmes size vibrator.
A straight razor with a hand-chipped flint edge.
Photo of Carrot Top labeled “Our Lord And Savior”
ohmy!
I was about to say Carrot Topp.
This is weird…
tamagotchi, complete with batteries
Now imagine a time capsule with ALL of these items in it. What kind of society would they piece together?
An Elvis painting on black velvet
I would think they’d pretty much nail it right on the noggin’.
Can’t we put in the “Dogs Playing Poker” painting? It’s my favorite. Really.
NO - it IS!!
A color printout of this web page. 
A stone box with “James, Brother of Jesus” chiseled on the face.
To really confuse them, I’d throw in a woolly mammoth skeleton. Maybe pack hamburger all around it so it’d have some “fresh” meat on it. Maybe they’d think we had giant cows roaming the earth.
Another time capsule, marked “do not open for another 25,000 years.”
A “Buddy Christ” Statuette and a copy of Dogs Barking Jingle Bells.
Can we put Bjork in it? Please?