A fire company certainly has a skin in the political game. Issues like funding, cancer presumption, relief association matters and many other items are largely controlled by our legislatures (both local, state and federal). Therefore, it is important that fire company leaders and members keep their fingers on the political pulse. However, any fire company with a tax exempt classification under 501(c)(3) (which is most of PA's volunteer or combination fire companies) must understand that participation in much of the political process is prohibited under the IRS rules.
Generally, there are two types of participation: (1) Lobbying and (2) Political Activity.
Lobbying is basically an attempt to influence (either in a positive or negative way) legislative activity. For example, the fire company may support the state's fire/EMS grant legislation or may want to stop some type of change to the relief association rules. Lobbying can be directly to a legislature or it can be messages to the general public. A fire company may, with limitation, lobby. The lobbying cannot be to an extent that it takes over as the primary activity of the fire company and the IRS has various ways to determine how much is too much.
The other type of political involvement is "Political Activity" which is basically endorsing a specific candidate (or party) in any way. This is strictly prohibited. A fire company cannot act in a partisan manner. Conversely, a fire company could do things such as hold an open roundtable discussion/debate if all candidates are treated equally being allowed to participate, during and after the event. There are ways to get the message out as to who is a friend and who is an enemy to the fire service but it must be done in a non-partisan way. It gets tricky when individual members, especially those in high-ranking positions, engage in Political Activity.
A fire company should have a policy in place to handle these issues before they arise and make sure all members understand it. It is important to have members who are participants in the process all while protecting the tax-exempt status of the fire company.
There is a sample policy on my Documents page. Make sure to consult your legal counsel to develop a policy specific to your organization and circumstances.