This would be great if it would work and not to be dangerous to humans!
Good point. I suspect that it would be easy to build or adapt an existing microwave generator that would kill termites in wood. I also suspect that it could ignite some wood in the right circumstances, and could leave it smoldering quietly inside walls, but I don't know about that. I didn't delve into real research on the subject, although if the OP is going to pursue the idea, I recommend some serious research on its hazards.
I do know from my own experience with very low power microwave detectors that microwaves are reflected by metal. This is one of the biggest reasons MW motion detectors were so prone to false alarms: Any metal surfaces in their coverage area would reflect the MW outside the coverage area, right through, e.g., drywall, glass, or wood walls.
So MW strong enough to kill insects, directed into walls, floors, and ceilings, could be reflected back by hidden wiring, pipes, various metal plates, nails & screws and whatnot within the walls, back out to anybody in the immediate vicinity. If you aim it at a wall with a large mirror on the other side of the wall, most of the MW radiation could be reflected back at you. Cooked brains, anyone?
There's a reason that MW ovens have not-easily-accessible switches on their doors so the oven can't be powered unless the door is shut and all the MW radiation contained. If those switches could be easily bypassed, some redneck idiot would turn him/herself into a vegetable sooner than later.
Not sure, but I believe you have to be a licensed (presumably trained) professional to buy microwave "pest control" equipment. I don't know if there's any law against making it yourself if you want to risk zapping yourself and/or your family. It's not something I'd want to play with, which is why I didn't pursue the research further.
