A positive and negative test in one BDD script

We have a GIVEN, WHEN, THEN structure to our BDD tests, but I have a requirement for a test which include both a positive and negative test.

Requirement: Produce a test which checks the functionality of the light switch.

GIVEN the light switch is off
WHEN the user presses the light switch
THEN the light turns on

This test is grate for testing that the light switch can be turned on, but is it possible to include turning the light off in the same script, or should that be a separate script?