Years ago, I had a flickering overhead light in the bedroom of an apartment I was renting. On closer inspection, I noticed a barely audible buzzing noise whenever the light flickered. After pulling the fuse, I removed the fixture and discovered a loose wire nut at the connection, which was still warm, even though the power had been off for quite a while. The wire nut and wires were black with soot from the arcing, which was the buzzing I had heard earlier. The building was about forty years old at the time, but I don't know how the wire nut loosened itself to cause the problem. I stayed there for about five years after that, but I was always on the lookout for any more electrical problems until I moved.
Fortunately, at the time I didn't have any sensitive electronics other than my computer, which was connected to a UPS. I would say that even if you have to pay to have your house checked out professionally, it should be done, just for your own peace of mind.
Bill in FtL
