Complete the online Speech request form at least six weeks in advance of your event. Please provide as much detail as you can on your topic of interest.We'll detail everything you need to know about how to invite a guest speaker, from the earliest planning stages to drafting a formal speaker invitation letter. Below is a sample invitation to an event that you can send to a legislator or candidate. Copy the text of this letter and update the items in YELLOW with your information to invite your member of Congress to visit. Sample Invitation Letter. We would be honored to have you as a speaker and would be grateful for the opportunity to share highlights of our research program with you. What are the basic components of an Invitation Letter for a Guest speaker? It is my sincere pleasure to invite you to speak at NRC's 23rd annual United States Nuclear Regulatory. Information Conference (RIC).