GFCI outlets are safety upgrades that every home should have. Houses built after 1993 are required to have these outlets installed in bathrooms, kitchens, and near any sink or washroom.
GFCI outlets are specifically designed to shutoff the moment it detects a leak in the electrical current such as the current traveling through a persons body. It constantly measures the outgoing current on the “hot wire” with the return current on the “neutral wire” and can shut down in as little as 1/30th of a second if the currents don’t matchup. Don’t wait to install these outlets.
Installing a GFCI oulet tutorial [Easy2DIY]
HowTo Install a GFCI Outlet [Corner Hardware]
Testing Your GFCI Outlet [CPSC]
Install a GFCI [Do It Youself or Not]