When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
If you use the search function at the top of the page you will find volumes of information on this. If you narrow the results, you will probably find more information in the General Maintenance section on this particular topic.
Just go to Search - Advanced and then search for security light under the General Maintenance section and you should get a lot of good results. There are also a number of good tips in the new members section.