No. You could do that with redstone repeaters and a circuit but then... you'd kinda need to be there so mobs would actually spawn. Mobs can't spawn more than 132 blocks away from the player, if I remember correctly.
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Watch out for the crabocalypse. Some say the day will never come. But it will.
If you'd like to talk with me about other games, here are a few I play.
Team Fortress 2
Elder Scrolls series
Left 4 Dead series
Dead Rising series
7 Days to Die
Just Cause series
Come to think of it, I mainly play fighting-based games.