AP: The White House was briefly evacuated Sunday evening while President Biden was at Camp David after the Secret Service discovered suspicious powder in a common area of the West Wing, and a preliminary test showed the substance was #cocaine. https://apnews.com/article/bd7a792357a85453cf55b6c955ff1b4f
Secret Service found cocaine at the White House when Biden was away, AP sources say

A preliminary test has shown that a suspicious substance found at the White House on Sunday was cocaine. That's according to two law enforcement officials. They spoke to The Associated Press on condition of anonymity because they were not authorized to discuss the investigation publicly. The White House was briefly evacuated Sunday evening, while President Joe Biden was at Camp David, after the Secret Service discovered the powder in a common area of the West Wing accessible to tour groups. The White House was soon reopened and the powder was sent for further testing.

AP News
Update: The cocaine was found in a cubby hole in a West Wing area where visitors leave their electronics and other belongings while taking White House tours, according to media reports.
Where the #cocaine was discovered "is a heavily-traveled area" of the West Wing which many visitors come through, says White House press secretary Karine Jean-Pierre.
There were "staff-led" tours in the West Wing of the White House on Friday, Saturday and Sunday, says the press secretary in responding to one of more than a dozen questions about the #cocaine discovery.
There will be drug testing of White House staff, if appropriate, adds the press secretary.
“The president thinks it’s very important to get to the bottom of this,” adds the White House press secretary.