... are maybe something given off when an interstellar ship engages a sort of 'warp drive'. The ship itself could be FTL. But the FRB created obviously moves at lightspeed.

Or that's my theory anyway.

Or it could be someones' wireless intergalactic door bell on their front porch... is there any payout on these theories?

No payouts, ever. We'll be turning the frogs gay by the time the answer actually arrives!