When my cats started "sparking", I knew it was time to get more moisture in my house.
I would set water out on the radiators to help. I even had an indoor dryer vent which was wonderful for helping to heat the house too. We had a very small house at the time that we had that.
You could try a vaporizor in the main room of the house, just make sure you keep fillilng it to get the moisture into the air.