Usually you have to spend thousands of dollars for an expert with the right equipment to focus on select areas of your home (areas that are suspect).
Are there ways to do a full-house scan yourself?
Swabs and a microscope. Oh and a degree in biology might help!
What sort of an indoor drone could this sensor be most usefully added to?
I've had success using my nose and a cheap $15 moisture meter against walls and ceilings. In my case I was already pretty sure the moisture came from the roof when it rained so went looking right after rainstorms. This was after also running a dehumidifier in a formerly damp basement.
If a home has an active mold problem, it probably has an active water or moisture problem. What mold remediation people sometimes do as well is use an IR camera to try to find unusually cold (thus damp areas).