Rotten Dead Smell in My House?

I have lived here almost 4 years. Starting yesterday morning there is a strong smell of rotten decay in front of the dish cupboard in my kitchen. It's built into an interior wall, with an open coat closet on the other side of the wall. No smell there or inside of the cupboard, just right in front of it. The basement below is open. You can look right up at the floorboards of the kitchen. No smell there.

At first I thought it was the garbage can sitting near. I took the garbage out which didn't smell and scrubbed out the can and sprayed, which didn't smell. My husband said he didn't smell it. I asked our 4 year old grandson if he smelled something stinky; he said no.

This morning the smell is worse. It's just in that one place. I don't think it's anything with me. If it were wouldn't I smell things in other places that I am at during the day? There doesn't seem to be any correlation between the smell and heater running. Yes we get dampness from spring thaws, but have a dehumidifier running in basement; it has been for the entire time we have lived here. Nothing has changed other than we have this smell now, that only I seem to be able to smell. Oh, and the smell does seem to come and go and vary in intensity. Any ideas?

By Judy K