I created the configuration files in ~/Library/LaunchAgents
When I attempted to load the plist, I got the message that the service was already loaded.
launchctl load ~/LaunchAgents/hosts_Blocksites_AM.plist /Users/bryan/LaunchAgents/hosts_Blocksites_AM.plist: service already loaded
When I attempted to find the Launchd agent nothing was returned.
$ sudo launchctl list | grep hosts_Blocksites_AM.plist
EDIT: fixed typo where I had:
launchctl load ~/LaunchAgents/hosts_unBlocksites_AM.plist