The refrigerator being a signal sucker is more likely. It would not suprise me that the electronic control board could have a capacitor on the power input as part of a surge protection circuit.
Something to consider is that both noise sources and signal suckers are additive. The refrigerator may be the "final straw" that lowers the signal level enough (or produces enough noise) to cause reliability problems. There may still be other devices that are contributing to the problem.
I was thinking about the 15A spec on your refrigerator. Does it say it pulls 15A, or it should be plugged into a 15A circuit? Refrigerator compressors are actually not that large. Like A/C compresses, they will pull a surge current when starting up (especially if it was not off long enough for the pressure to bleed down). However, the running current should be well under 15A, and perhaps even under 5A. That said, you still have to size the filter so the surge current will not burn it out.
Jeff