Hi. I'm in a quandary. For the past few months I hear, at intervals, a loud buzzing or vibrating from the outside wall. The noise lasts only a few seconds, but it is loud. Today it is happening repeatedly.

We are in the throws of a serious snow storm this week, which makes me even more nervous about this situation because if it's electrical, this would be the worst time to risk a fire.

Thanks for your help.