Secrets & Mysteries was an American television series that syndicated from 1987 to 1989. It was a paranormal magazine show, often compared to In Search Of... which ended it's run five years before Secrets & Mysteries premiered.
Although the topics were similar in nature to In Search Of..., and Secrets & Mysteries certainly released around the same time, it appears great lengths were taken to separate the two shows. Secrets & Mysteries incorporates bumpers hosted by Edward Mulhare, which show him using all sorts of gadgets and pseudo-futuristic technology to help display information throughout each episode.
I'm not certain what TV stations aired Secrets & Mysteries during it's syndicated run, but the show appeared to make its money on video. Tapes were sold in different formats from the late-80s all the way to the early-2000s. Each episode was released individually, there were several sets that had four episodes to a tape, and there were even two Blockbuster Presents editions, each with two episodes on each tape (one of which I'm highlighting here). The show was never released on any other format, nor is it available on streaming.
During its video run, it seems the title of the series was changed to Secrets of the Unknown. This isn't entirely consistent, though. For instance, on the Blockbuster Presents: Secrets of the Unknown: Bigfoot & Witches tape, the "Bigfoot" episode is presented as Secrets & Mysteries on the intro and outro, however the "Witches" episode uses the Secrets of the Unknown title for the intro (which interestingly runs at a different speed than the Secrets & Mysteries introduction) but then uses the Secrets & Mysteries title in the outro. Having watched a few different episodes of this show on tape, there seem to be all sorts of inconsistencies with how the episodes are presented.
You can find out more information about the series on Wikipedia.org.
You can find video clips of the intro and outro segments on my video archival channel, VHYesterdayS.
I've also uploaded the full videos for both the "Bigfoot" and "Witches" episodes on the Internet Archive for archival purposes.