“Lucifer” star Tom Ellis and his screenwriter wife, Meaghan Oppenheimer, got a devil of a scare in the mail … cops are investigating a strange package sent to the couple.

Law enforcement sources tell TMZ … someone sent a glitter package last month to Tom and Meaghan’s Los Angeles home, and we’re told the couple found the delivery creepy enough to call cops and file a police report.

We know what you’re thinking — what the hell’s a glitter package??? We’re told it was a box filled with glitter, which might not sound all that menacing — however, what concerned the…