If you can get someone out there with a spectrum analyzer such as Ekahau sidekick with software it can triangulate to help locate things, but yes you are looking for all kinds of things in 2.4GHz like microwave ovens, bluetooth, wireless door bells, cameras, and many others. This will give you some clues of what to look for: https://www.ekahau.com/blog/identifying-wi-fi-interference-with-ekahau-analyzer/ Good luck.
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