The Internet allows for the efficient dissemination of texts, thereby creating a rich hypertextual environment that is potentially conducive to stimulating the free exchange of ideas in a manner worthy of the modern scholar. However, the fact that any user whatsoever may disseminate texts in this manner presents two distinct problems. First, finding electrical switches on the Internet may take a fair amount of time and, second, once resources are found, determining their reliability is often difficult if the user is not already an expert in the field of the resource under consideration.
The world of subject directories and search engines is a highly volatile one. Don't be dismayed if you search electrical switches,and discover that things have changed. This is part for the course. Many of these sites are commercial enterprises and competition is keen. When changes occur, they are often for the better as the service attempts to keep ahead of the pack. Enjoy the ride!