I'm replacing my whole-house wired intercom system with a home-brew system I'm currently designing. The stations are connected to the master station using 6-wire (3 twisted pairs) cable. I will be using one pair for power, one for data, and one for audio. The question I am currently dealing with is, what should I use to protect the circuitry from large voltage spikes caused by near-by lightning strikes? I recently had an experience that showed me first-hand how large these can be. I had pulled a pair of wires out from behind the cabinet of one of the existing old stations to test something and they were currently not connected to anything. They were just hanging there, bare ends maybe about 1/8 to 1/4 inch apart. During a thunderstorm we had a near-by lightning strike and I saw a spark jump that gap. I was amazed, though I don't know if I should have been. This is an area I have no experience in. Searching online for surge protection I get info for MOV, TVS, TSPD, etc, etc. I'm not sure where to start. I understand some of these can wear out over time. Can someone give me a recommendation? Keep in mind I am doing this on a hobbyist budget.