From the Richard Brautigan Bibliography and Archive:
This poem was found written on a paper bag by Richard Brautigan in a laundromat in San Francisco. The author is unknown.
By accident, you put
Your money in my
Machine (#4)
By accident, I put
My money in another
Machine (#6)
On purpose, I put
Your clothes in the
Empty machine full
Of water and no
Clothes
It was lonely.
Paint Fumes 
Talk about “found poetry” !!!!
Hey, I wanted to tell you that I signed my son up for an art class day during his spring break. He chose a dragons class and a secret code class. They will be venturing into the museum to see some of the relevant art and then scamper back to the studios to create. He is really psyched that he got his first choices!
I wonder if Brautigan wasn’t pulling everyone’s leg with the statement about finding it in the laundromat- both the poem and the denial of authorship of pretty Brautiganish:) Who knows.
Your son’s classes sound fun! I hope he has a great time.