An insulating block configured for attachment to an electrical structure without the use of a tool. The insulating block is formed from an electrical insulator. One of the electrical structure and the insulating block may have a clip that is configured to engage a catch surface on the other of the electrical structure and the insulating block without the use of a tool. An opening or recess of the electrical structure may be configured to receive a portion of the insulating block having the clip or catch surface, and the portion of the insulating block may move within the opening or recess from a disengaged position to an engaged position, in which the clip engages the catch surface to securely attach the insulating block to the electrical structure. The electrical structure may be a meter socket enclosure. The combination of the insulating block with the electrical structure.