The phone box's ground wire goes into the basement, and it was connected with a clamp to one of the hot water pipes. I thought that perhaps that was part of the problem; perhaps the water heater was interfering with having a direct path to ground. So I considered moving the ground wire over to the cold water pipe instead. Then I remembered that after I moved in, I had a plumber install a shut-off valve on the main water pipe coming into the basement. When he did that, he replaced a small section of the original metal water pipe by the new valve with a section of plastic pipe. So it is possible that before then, the water pipes were grounded, but afterwards, they no longer were. So I installed a new ground wire going from the clamp on the hot water pipe out to the grounding rod outside. Maybe I should have just removed the original ground wire from the phone box, and connected the new wire directly to the box instead of to the pipe. I'm not sure.
Now I shall monitor my phone line over the next few days to see if the static is gone. Here's hoping!!
Now I shall monitor my phone line over the next few days to see if the static is gone. Here's hoping!!