wiring and breaker/fuse panel. it is likely your bulbs are blowing so frequently due to extra stress placed on them due to improper voltage conditions and excessive fluctuations of voltage to them due to perhaps a poor neutral or some other electrical cause. Another thing to consider checking is with the power company--tell them what has been happening and ask them to verify stable voltage regulation in the power company tranformer feed to the house---this could be your problelm too but it not likely. good luck LJ