A surgical instrument includes a switch base, a power bus coupled to the switch base, an electrical lead coupled to the power bus, an actuator operatively engaged with the power bus, an actuator operatively engaged with the power bus, a membrane, and a housing. The switch base has top, bottom, and side surfaces. The membrane is disposed over the top surface of the switch base and over the power bus to seal the top surface of the switch base. The housing defines proximal and distal ends and a switch base cavity between the proximal and distal ends. The housing includes bulkheads that form a plurality of fluid impermeable seals that are disposed adjacent one of the proximal and distal ends. The fluid impermeable seals are configured to deter fluid from penetrating a proximal portion of the switch base cavity within which the electrical lead is coupled to the power bus.