Is it possible to find fire outside the Earth? Excuse me if the question is silly, I have very little knowledge of chemistry.
We can find oxygen in many places in the universe, but all the combustibles we use to light fire seems to be organic: carbon, oil, wood, alcohol... so if that is true, we could only find fire on Earth, as long as we don´t find organic materials in other planets.

Another way of asking the same question could be: can we light a fire without organic material?

Note that I mean fire as a result of a combustion. The Sun would be a non-valid example, as it works by fusion.
Many non-organic substances burn. For example:


Reactive metals such as potassium burn when exposed to oxygen. (Thanks to @Jon Custer in his comment)
Non metal elements such as carbon, sulphur and phosphorous also burn in oxygen when heated.


So yes fire is definitely possible outside earth.

Additionally simple organic compounds such as methane are known to exist in large quantities on other bodies such as Titan, a moon of Saturn, which has a whole 'hydrological' cycle based around methane, and to a lesser extent ethane and heavier hydrocarbons, with a methane atmosphere and lakes of methane on the surface. (Thanks to @ron in his comment)