L.A.
I've seen a couple like that. They usually post signs just like a garage sale would, but it says "Indoor" garage sale.
Then block off the other rooms (use streamers or something), and have everyone come in to the room you are using, preferably closer to the fron of the house.
Be sure you have lots of big signs in your yard, with balloons tied to a chair, and a sign that says "come on in" or "please knock". That way. when people drive to glance down the street, they will see that it is still going on.
The one I went to the front door was kept open, and the lady basically sat by the entry welcoming people, and she had friends helping her out as well.
(Estate sales are when almost EVERYTHING in the house is for sale, usually following the death of a relative or a whole house moving sale, so I wouldn't consider this an estate sale).