I just got thru modifing a grave stone I bought from walgreens. I cut out the fake flames and filled in the holes with a flicker bulb and socket.
I'm not very electrically or mechanicaly inclined so I mostly just buy premade props and modify them a little to make them more realistic.
Here is a pic. showing the right side with how it come and then the leftside after I installed the flicker bulb and socket.