https://spinoff.nasa.gov/FINDER-Finds-Its-Way-into-Rescuers-Toolkits

You are correct because something similar has already been used

https://spinoff.nasa.gov/FINDER-Finds-Its-Way-into-Rescuers-Toolkits

Microwaves are the same as wifi waves, these are able to detect bodies and whether the bodies are beating or not

Who has had this happen to them?

Could you post some pics of the trashcan? Sounds cool, might want to make one