I was in the MATV/CATV business for many years in the 70's and 80's and never heard of anything like this.
We did have somebody complain that when they selected channel 19 on their cable box that their garage door would open. I told them that the cable company usually charges extra for that feature but I won't tell them that you have it. Never heard from them again.
Strange as this sounds it could be similar to your problem. New appliances these days have electronics and microprocessors controlling them instead of an old fashioned thermostat. Electronic controls can generate RFI as a byproduct of their operation. Since you mentioned that there is a "booster" or amplifier for the antenna it indicates to me that the off air TV is pretty weak to begin with. I don't know where he placed the "noise filter" but my guess is that all it did was reduce the TV signal even more. Under those conditions an RF signal of the right frequency and strength can overload the amplifier or "beat" with an off air frequency. Either way the result is interference.
The fix probably isn't going to be easy. Because you have this problem probably means that your off air TV reception isn't that great to begin with. Yes, I know it worked fine for years but one thing I learned early on is that people have widely separated opinions on what is acceptable as far as TV reception is concerned.
The first thing I would do is make sure the antenna, cables and connectors are in proper order and the best they can be. I can't tell you how many times I have seen connectors that look like they have been installed with pliers or a hammer. The ideal location for the "booster" amplifier is on the antenna itself not some distance away. We always use a signal meter to set up and check our systems. Anything much below 0dB at the set could be a problem.
Sometimes the off air signel is so down in the dumps that nothing will help. You can only do so much with an amplifier, you can't make something out of nothing in which case the amplifier only makes things worse.
This may be the case here and if so the solution is cable or satellite TV.