electro-hydraulic v electro-pneumatic
When it is said that a component is electrically controlled but hydraulically actuated it simply means, as you said, an electrical signal is sent to the controlling element of the component and this action allows hydraulic pressure to actuate the component. The same principle applies to those components which use pneumatic supply to actuate the component, i.e, electrically controlled, pneumatically actuated. As nncO says, bleed air valves are a classic example.