Former The Walking Dead leading man Andrew Lincoln was present on set during the filming of last Sunday's 912, 'Guardians,' as revealed by a behind-the-scenes photo shared by the Walking Dead Twitter account.Look who was on set of last week's #WalkingDead ? pic.concours-twitter.htm">twitter.com/8mssq5oFUK-- The Walking Dead (@TheWalkingDead) March 8, 2019Filming wrapped on Season Nine in ...