Insulation, Radiant and Vapor Barriers - wall insulation

I'm new to this site and have a lot of questions, but I'll start with keeping warm. I've got an old farm house, built in the 20's or 30's. the walls are sheathed with 1" x 4" inside and out, but there's no insulation in between, there never was. The old place is hard to keep warm and hard to keep cool. I've looked at blown in celulose, but have heard that it settles. If so, how often does it need to be re blown to maintain or fill up?

I've also looked at slow expanding pour / spray in foam. That sounds best, but does it cause any problems with wiring / junction boxes / receptacle boxes, etc. Also, does the foam cause condensation?

Any advise would be welcome

thanks,

hal

Guess I'll just wing it. Thanks for looking any way folks.