Could you elaborate on what you mean by lava dripping from the ceiling? Do you mean a large flow of lava continuously streaming down, or do you mean individual droplets? If your answer is the former, you could make a displacement to create a waterfall, and use a 'moving' texture to simulate the flow of lava. A tutorial for that can be found
here. If you want the latter, you'd have to make a custom info_particle_system, or use an existing one. I've never really heard of anything similar to what you want, but you are welcome to look under
here to find anything. As for making a custom particle system, I haven't the slightest idea on how you would go about doing that. Here is a
TopHATTwaffle video on the basics, but I'm not sure if this would be pertinent to what you are trying to accomplish. There's always the
Request Area, where you can ask other modelers and mappers kindly to make you something, but this would most likely would cost money, so use this as a last resort. I hope this helps!