Identify a tool commonly used to operate a mechanical switch.

A switch lever is indeed the most appropriate tool commonly used to operate a mechanical switch. This lever is specifically designed to engage or disengage the switch, allowing for precise control over the operation of track switches in rail systems. The switch lever typically provides a mechanical advantage, enabling the operator to change the position of the switch easily and safely, especially in situations where manual effort is required.

Other tools, while they may have their own uses, do not serve the same function. A manual lever might suggest a broader category of tools and could include various levers, but it doesn't specifically refer to the device intended for switches. A hydraulic press is used for applying force in various applications but is not designed for operating switches. An automatic timer may control electrical devices but lacks the direct physical interaction with mechanical switches that a switch lever provides. Thus, choosing a switch lever directly aligns with the specific action needed to operate a mechanical switch.