The correct Active/Passive form of the given sentence is:

☀ The electricity should be switched off when changing a fuse.

 Explanation for other options:

☀ The electricity shall be switching off when changing a fuse. This option uses "shall be switching off," which is not the appropriate passive form. The correct form should be "shall be switched off."

☀ The electricity shall be switching off when changed a fuse. This option uses "changed a fuse," which is not the appropriate passive form. The correct form should be "when changing a fuse."

☀ The electricity has been switched off when changing a fuse. This option is in the passive voice, but the tense is incorrect. The original sentence uses "should switch off," which indicates a recommendation or advice. The correct form should be "The electricity should be switched off when changing a fuse."