Brick 2 x 2 cash register and tile 2 x 2 tape recorder sticker
Assuming these stickers are applied to the correct parts, you can search on Bricklink in the following categories: Slope, Decorated and Tile, Decorated (these links start at the pages where 2x2 slope and 2x2 tile first appear, respectively).

I didn't find anything looking like yours, which can mean one of three things:


I didn't look hard enough (there certainly are a lot of decorated 2x2 tiles)
These are not official LEGO stickers
There are official LEGO stickers but applied on wrong parts.


I'm leaning towards them not being official stickers, but there's no real way to be sure until we find where they are from.