Whole House Fan Repair/Replacement - any recommendations?

Hello! We have a whole house fan that's installed in the ceiling below our attic (the kind that sucks all the air out of the lower floors and replaces it with air from outside when the windows are open) that just stopped working, and we need to have it repaired or replaced. Does anyone in the neighborhood have any leads on companies or specific people who have expertise with these types of fans? We’re not coming up with much online, it seems like a very specific niche service area! I’d be so grateful for any references if anyone has them. Thanks - Megan