Sorry, was off on the wattage--this is on ebay, you can get these at automotive parts places and probably some supermarkets.
http://cgi.ebay.com/2-PK-Kirby-Vacuum-light-bulb-fit-Classic-1CR-and-Older-/180636970137?pt=LH_DefaultDomain_0&hash=item2a0ecd6c99#ht_3099wt_833
This is the type of bag...