Multi-purpose dry powder or Aqueous Film Forming Foam (AFFF) are probably the best choices. They are come in small enough sizes to be installed without making your home look like a factory and extinguish common domestic types of fire.

Something like a 2ltr AFF foam fire extinguisher or 2kg ABC powder would be best in our view.

You can if you want add a 2kg CO2 extinguisher near a major electrical hazard such as IT equipment, kitchen or electrical cupboard.

Benifit over foam or powder would be no mess (other than that the fire makes) but downside would be it's not rated for Class A (wood, paper, textile) fires which are common domestically.

If you are unsure please feel free to drop us a email