I just purchased a used LEGO Studios set and had some extra pieces that don't belong
It's tough to predict where such a small number of pieces came from, but some are likely from the Hydronauts theme, specifically Hydro Crystallisation Station (6199):



This set includes the chromed headgear with studs on the back as well as the printed tile that is already attached to the back of yours.

The minifig utensils are likely from Mobile Outpost (6520):



Here are links to the sets that these parts appear in if you'd like to explore this more:


3069 - Tile 1 x 2 with Copper and White Circuitry, Red Rectangle and 4 Squares Pattern
71598 - Chrome Blue Minifig, Headgear Helmet with 2 Studs on Back
6041 - Trans-Neon Green Propeller 3 Blade 3 Diameter
2569 - Trans-Neon Green Antenna Whip 8H
6040 - Black Propeller Housing
30193 - Dark Gray Minifig, Utensil Ice Pick
3837 - Dark Gray Minifig, Utensil Shovel (Round Stem End)