In white supremacist circles, the ghost skin short for 'ghost skinhead' is the white supremacist who refrains from openly displaying his racist beliefs for the intention of blending into wider society and surreptitiously furthering his agenda. The term has been used in specific to refer to the entryism of racist activists in law enforcement.
In an FBI Intelligence Assessment from 2006, the FBI Counterterrorism Division reported an overview of white supremacist infiltration of law enforcement & mentions that usage of the term came to the agency's attention in late 2004. In 2001, two law enforcement officers in Williamson County, Texas, were fired after it was discovered that they were members of the Ku Klux Klan.
According to the Oregon National Socialist Movement website, explicitly cited by the 2006 FBI report, "Ghost Skins don't shave their heads, wear boots, braces or anything else that can visually identify them as Nazis. [They] strive to blend into society to be unreconizable [sic] by the jewish [sic] enemy. When it serves [their] purposes [they] gladly act politically correct. [They] are at war and [they] usage the weapon of deception to deny the enemy intelligence they could use against [them]."
On September 29, 2020, Jamie Raskin, the Chairman of the Subcommittee on Civil Rights and Civil Liberties, released an unredacted representation of an FBI explanation called White Supremacist Infiltration of Law Enforcement.