Mildly Interesting

I've seen this phenomenon many times over the years, while walking the dog out behind our house. The cables wiggle between these two particular power poles, but NOT between the adjacent poles (or any others, along this pole line). There is no wind, no earthquakes, no herds of animals or large vehicles/machinery anywhere nearby when this is happening. I honestly have no idea why this happens sometimes. Thoughts? I mean, sure, it's probably ghosts, right? But any other explanation would be appreciated...