I'm going to leave my neighbors wet clothes on the washer
Why are you doing your neighbors laundry?
She lives alone in her house and I want to be cruel to her.
You should be considerate of your neighbor. You can always tell them about their wet clothes. They would be happy that you're looking out for them.
I'm probably going to do it tomorrow so I can either get a rise out of them or I could just not say anything if they figure it out.
It would be easier if you just tell them when you have the time and remind them to always check their laundry.