I know that “Estate Sales” are supposed to be different than “Garage Sales” and they must ask for permission plus there is a limited time period. Perhaps those rules can be put out to the community.
If they are a “legal”estate sale then perhaps it might be an idea to have conforming SCA directional signs available for purchase at the membership office and limited to the number of turns necessary to find the address.
However most residents have GPS or a map so we don’t need signs on every light pole. We do have ad space available in our RELAY in the SPIRIT magazine for sales as well.