Arctic Silver is a fine product, and they have solved their problem of electrical conductivity with the production of their AS5. But, the earlier products did have some trouple in that area.
Negligible electrical conductivity.
Arctic Silver 3 was formulated to conduct heat, not electricity. It is only electrically conductive in a thin layer under extreme compression. (While much safer than electrically conductive silver and copper greases, Arctic Silver 3 should be kept away from electrical traces, pins, and leads. The compound is slightly capacitive and could potentially cause problems if it bridged two close-proximity electrical paths.)