Yes non vented kerosene heaters can be used inside a home for emergency heat.
A non vented kerosene heater will produce carbon monoxide so you should only use a non vented kerosene heater as a temporary emergency heat source in your home.
Also when using a kerosene heater that is not vented you need to allow some fresh air into the home through a slightly open window.
Just open the window a small crack to allow some fresh air in because the kerosene heater will take the good air away and replace it with carbon monoxide which is a deadly thing that you cannot smell.
They do make vented kerosene heaters too that can be used long term without the need for venting a window.
I would recommend installing a propane or natural gas vented heater that does not require electricity in the event you have a power outage and your regular furnace does not work.
As long as you use the kerosene heater safely you should be fine.