Hi, why the fire particle light is under the floor?
On the floor:
http://puu.sh/b8Rot/9bd305f467.jpg
Under the floor:
Hi,
There is no direct silver bullet to this other than to adjust some of the settings in your particle system. Unlike point and spot lights the radius for your particle light is very important because it is not stopped by geometry.
In your particle light module you’ll need to adjust the radius to be something smaller. Something closer to the bounds of your particle system.
Under the light module > select the check box for Preview Light Radius > then Radius Scale down arrow > Distribution down arrow > adjust the constant value until it is closer to your mesh. This may seem not as bright but you would want to use non-shadow casting point lights to add some other lighting to your scene.
This should help you get started. If you have any other questions feel free to ask! 
Tim
A good fire effect usually involves the lighting of the particle system as a kind of highlight or added effect on top of the actual point light you’re using to represent the fire. Especially for fires that are always burning, this gives you the ability to lightmap the point light. Light mapping gives you reasonable bouncing and yet you still get some dynamicism in the flickering.