This is my first post and I apologize if this has been asked before recently. I did a search but did not find anything about this subject though. I hope someone will have some knowledge of this problem, possibly some advice or help in solving the mystery!
For the first time ever, we noticed a low humming inside our house that never stops, about 2 months ago. It is either a constant low hum or one that goes for approximately 5 seconds, stops for 2 seconds, then restarts over again. There is no pattern except that we notice more of the constant hum at night, but that does change. Some people that visit our house say they can hear it, others say they can't. And there is no difference in the hum level from one end of the house to the other, it is at a constant level.
We have turned electrical things off but we still hear it. We do not notice it outside but that could be because of the outside noise in general. We do live on a well traveled street and hear all kinds of sounds when outside, but when inside we always hear the hum. The traffic and sounds in our area have not changed within the last 2 months that we can tell of when outside. And we cannot think of anything that has changed in our electrical output, etc. during the past couple of months.
Any suggestions? Thank you!