"stationary closet" has slightly more hits than "stationery closet"; neither has very many. Though with "cupboard" the reverse is true.

looking at how many of the top umpteen hits for "stationary" are actually about stationery is interesting.

Reminds me of my Physics GCSE, which talked about a car that was stationery... or something like that.

The world is ending if even standardised exams get this stuff wrong.

I should hope that very few closets weren't stationary.

I can't remember whether it's apocryphal or whether it actually happened at my company, but the classic one of these is the internal office email with the subject line "The stationary cupboard has moved" :-)

"Do you sell Stationery?"

"No, sometimes I move about a bit".

Boom Boom.

There's a stationery factory just outside Sawston which we drive by sometimes, and I like to imagine a misspelling on the sign leading to it driving off in disgust. It's by the railway, so I imagine it would become long and thin and trainlike.