I've talked about this partnership in the past, and if you have the ability to create such a partnership with your local public safety folks, I highly recommend it. Kids especially enjoy getting to see inside an ambulance.
If you don't have the ability to create this sort of partnership, however, that doesn't mean you can't tie some Halloween safety tips into an October program. Compliance and Safety shares some free tips for staying safe on Halloween addressing topics from costume safety, to food and candy safety, to other relevant details for families that may be planning to trick-or-treat. These are great tips to know from a reference perspective, and they can also make helpful asides in a Halloween program.
I know that different libraries include (or don't) Halloween in different ways in their story time programs, from incorporating a single Halloween-themed story and craft into story time, all the way through having kids dress up and trick-or-treat through the library. Regardless of what your library does, consider making these Halloween safety tips available to the families you serve in some capacity. I've found that parents really appreciate the tips, and they also appreciate that the library cares about the safety of their children outside of library time. These small details really help us to build strong relationships with our service populations.