Having had to replace an entire septic field due to broken drain tiles or poorly installed draining can be a real chore not to mention expense. I hope the best for you and please let us know if you ever do determine the source. If I can suggest a home remedy for the stench- Using four small (6-10 oz ) glasses or jars and ordinary wine vinegar.
Pour about 1- 1 1/2 to 2 inches into each of four "cups" and place these, one in each corner, of the room that reeks. Allow at least an hour prior to checking results. More time may be required but this is usually about 2-3 hours max. ***We have a rental that apparently a stray cat had found a way into but never left before death .
When we opened the house after being vacant for a month the smell was horrid. I tried the solution suggested and found it worked very well.
Too difficult to answer without an on site inspection. Are you on a septic line/field? Any animals living under the house?(skunks, raccoons, rats, squirrels, badgers)Maybe you have a leaking sewer line.
Or a dead animal. Would have to see the site to know... and do some smelling.
If it smells like rotten eggs, it's sewage related. Check your vent pipes on the house roof. Be sure an animal hasn't built a nest in them.
Cold down drafts force the methane odor back down to grown level and into the house.. Also, if you have propane for any appliance, have the gas company check everything for leaks. Also, just a thought, check your dryer vent pipe. Mice love to build nests out of the dryer dust material and can make them under the dryer.
You may very well have a dead rodent in the wall behind the cabinets. Squirrels are famous for this.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.