Klosterman said a burning smell could indicate an electrical fault in your appliances, wiring or outlets, and in worst-case scenarios, these faults could lead to electrical fires. Take your clothes dryer, as one common example. 

“If there’s a burning smell, that means the lint needs to be cleaned out of that [dryer]. You don’t want that to catch on fire,” said Duane Enoch, owner of Green Air Concepts Heating and Air Conditioning in Ardmore, Pennsylvania.

You should regularly be cleaning your dryer’s lint filter and dryer vents, because a failure to clean was the leading cause of why clothes dryer fires happened in U.S. homes from 2018‑2020, according to the U.S. Fire Administration. 

“If you smell burning plastic or any electrical odor without an identifiable source, disconnect power and contact an electrician,” Klosterman said. “Take time to familiarize yourself with the location of the electrical circuit breakers in the home. Each breaker should be individually labeled to designate the area where electricity is being channeled.”

8. Sweet, Syrupy Smells From Your Air Conditioning Unit  

Source: https://www.buzzfeed.com/monicatorres2/dangerous-house-smells