Are there any low-EMF house security systems that you recommend?

I don't have a particular brand in mind, but if I had to get a security system for my entire home, I would simply look for products that can be "hardwired" instead of "wireless".

Ironically, wireless security systems can be hacked into, and a pose a real security risk. That's on top of the wireless radiation that you add all over your home via various sensors, cameras, etc.

These days, wired security systems are generally geared towards industrial buildings, but there certainly are certain companies that will install these solutions in a residential context.