All previous comments are ALL usable. My contributions are:
--under the door sills at the front and back doors. Individual coins can end up under the sills from years of the floors being swept clean. Also, check outside the back door within several feet for coins "thrown" outside when wives swept the dust/dirt outside.
---Check behind the covers on the openings where stove pipes go through the walls. Also, some of these covers are highly collectable. There were decorative covers made specifically to close off these openings when natural gas and propane became popular for home heating. These covers might resemble kitchen trivets. (which are also collectable)
---Check the backs of kitchen cabinet drawers. Paper money has been found tacked to the outside faces of the drawer backs. (also tacked to the bottoms) Take out all drawers and check.
---Trap doors in the floor in the back of kitchen cabinets.
---Unusually short sections of shoe mouldings at the base of a wall.
---Under stair treads and behind stair risers.
---Under clothes lines.
---The band of lawn within 4 feet of the edge of any porch. I've found "nest" of coins in this area left by kids playing just off the porches.
---If the house is at least 3 feet off of the ground, crawl underneath and look for coins and old toys. When I was a kid, that's where my friends and I would play "trucks and cars" because the dirt there was easy to dig in and NO GRASS to worry with.
We'd make roads and little caves to park our trucks and cars in. We'd use big spoons to dig with.
---Look for old printed material such as calenders and advertisements. Old print material is collectable. There are some folks "out there" who collect this stuff.
---A good guideline to follow is: if it is old and identifiable, someone somewhere collects it.
---Feel along the top of all doors. There have been cases where people have drilled coin-sized holes in the top of doors to fit stacks of coins into then seal off with plugs made from wood or wood putty.
Start at the top of the house; section off each floor into manageable pieces and thoroughly search that section, then the next section, etc until that floor has been completed. Done this way, you'll be assured of hitting every square inch. If you do a hit and miss; running around like a chicken with its head cut off kind of search, you will be an amateurish loser. You need to open your mind and LOOK around you. Some types of old door knobs and face plates are surprisingly valuable.
I and these other posters have barely touched on the possibilities.
