Those tone probes are so fun to play with! I highly recommend anyone with a spare $15 to grab a cheapo model and just... run around the home with it. It's an en

Those tone probes are so fun to play with! I highly recommend anyone with a spare $15 to grab a cheapo model and just... run around the home with it. It's an enlightening experience to actually perceive with your own ears the normally invisible world of EM radiation