Can I sell personal items in the US while on Visa waiver?

Question

Without breaching conditions of the WV, of course! For example:
A: Selling old clothes of mine
B: Artworks eg original paintings

I am thinking of ebay, in theory.

Answer 1

I'd be careful with the original paintings. The old clothes sales aren't really "income", but selling your own art work probably is, and you'd need to report it, or have a really good story ready when they come ask why you didn't.