Both eBay's original Trading Assistant Program and its later eBay Valet program failed. They failed because there are so many pitfalls, problems, and potential liabilities in selling for others that it's hard to find an experienced seller who will attempt it.
It starts with the emotional drama that develops because people nearly always have an unrealistic idea of the value of their stuff. Then in continues right on through the credit card chargebacks customers make six months, or more, after a sale.
So, you won't find anyone through these forums. You can try advertising locally, but only if you are willing to pay someone by the hour or per item listed for his time. Forget the "percentage" idea, as X% zero is still zero, and there will be plenty of items that do not sell.
If you do find someone willing to do this, be sure you have a clear, detailed, written contract.
