Sometimes there is a residual smoke odor from a small fire that is annoying and lingering. Short of a good cleaning of everything in the house, you can place small saucers of household vanilla, wine, vinegar or activated charcoal about your home to help absorb these odors. Remember that the smoke is also inside the heating and cooling duct work and you get a fresh blast every time your air system is turned on.
If insured, consult your insurance company for assistance. If the odor does not go away in about a week, you may, and probably should, call a janitorial supply or cleaning service specializing in restoration of fire damaged property (refer to your yellow pages, under Fire and Water Damage Restoration). They have the equipment to scrub out the duct work and deodorize everything in the house.