Pilot light

The pilot light is a miscellaneous item in Fallout 3 and Fallout: New Vegas.

Characteristics
It is one of the several scrap items that can be used in the construction of weapons and ammunition using schematics. In Fallout 3, one is needed in the creation of a Shishkebab. In Fallout: New Vegas with the Dead Money add-on installed, one is required to craft a gas bomb and the Cosmic knife super-heated.

Fallout 3
You can easily find these by searching ovens (found in many abandoned houses, for instance in Minefield), or they may also be found in some workshops. A pilot light can be obtained early in the game by searching through Silver's stove inside her house in Springvale or in the RobCo Facility.

Fallout: New Vegas
Similar to Fallout 3, pilot lights in Fallout: New Vegas can be found in ovens. You can find many more in the basement of the REPCONN Test Site, especially in the storage room in the south-west. There are also several of them lying on the floor across the whole basement.
 * One can be found in Nelson house
 * At Novac(Jeannie May Crawford's house)(oven).
 * One can be found in oven at Fields' Shack.
 * In an oven inside a house in Goodsprings.
 * Some can be found in Novac near the gas station, on top of the shelves