Wiring for Light switch in sump pump room
NEC 210.70 Lighting Outlets Required  210.70(3) Storage or Equipment Spaces ...control shall be at the usual point of entry to these spaces...The lighting outlet shall be at or near the equipment..
A sump isn't specified as needing a dedicated circuit, but circuit ampacity, location of disconnecting means, and manufacturer instructions would come into play for the exact pump installed. If the sump is considered NEC 210.23(2) Utilization Equipment Fastened in Place it can't exceed 50% of the branch circuit rating of a shared circuit. Otherwise if not fastened in place then a cord connected plug is limited by NEMA and NEC 210.21(B)(2) to 12A on 15A plug and 16 on a 20A so circuit capacity to add lighting could be assumed adequate. AHJ interpretation could come into play.
If your installation or circuit ampacity requires a dedicated circuit for the sump, then Section 210.8 which specifies most of the locations GFCI protect is needed applies to receptacles not lighting outlets (at least through NEC 2017).