cmos chips is the simple answer.  Learning cmos is the complicated drawn out version I still have as yet to master.

Another option is checking your local dollar store.  I found 'flickering led candles' for $1 each.  They are orange and flicker like flame which will be perfect when I do something similar to what you are going for. 

A more expensive version of that is to hit your local train shop as they will have prewired stuff like that in many train scales.  Expect to pay mondo moola though, relatively speaking.