“The Voice” is about to meet the iconic singer who earned the nickname the Voice. The late Whitney Houston will reportedly appear on the NBC singing competition in holographic form, reports Entertainment Tonight. The news of the posthumous visit comes after rumors swirled on social media last week that the show’s judge Christina Aguilera would perform a duet with a 3D moving image of Houston. Aguilera declined to address the speculation but promised a grand finale this season — which will air on May 24. “I am sworn to secrecy,” the “Fighter” singer told the gossip site. “I can’t say anything, but I’m very excited about the finale. Very exciting…