Lighting a Drift Globe is a free speech action
The DMG under Activating an Item says:
Activating some Magic Items requires a user to do something Special, such as holding the item and uttering a Command word. The description of each item category or individual item details how an item is activated.
If an item requires an action to activate, that action isn't a function of the Use an Object action, so a feature such as the rogue's Fast Hands can't be used to activate the item.
From this we understand that if activating an item requires an action it will say so. The same would apply to using a bonus action. This places it now outside of actions into either object interactions or free actions. Generally speech is a free action, so there is no reason to think this would be anything other than a free speech action.
