COCAINE discovered in the White House was found in a cubby hole in a West Wing entry area where visitors place electronics and other belongings before going on tours, a source familiar with the matter said. The Secret Service is investigating the matter, the White House said. "They're checking visitor logs and ... looking at cameras. Those are the next steps. Cross-checking" said the source. White House spokesperson Karine Jean-Pierre told reporters: "Where this was discovered is a heavily travelled area where many ... West Wing visitors come through." Asked whether anyone had undergone drug testing as part of the…