Over-sensitive keys on laptop keyboards are actually a not-uncommon problem that can happen for a multitude of reasons. There's often something under the key interfering with the action of a particular key. There are other reasons as well--sometimes sticky fluids will get under a key and interfere with its action or cause electrical problems. As this is a fairly common problem, it's fairly easy to fix.
Turn off and unplug your laptop, then open it and blow compressed air under the keys.
Turn the laptop upside down and move it around to dislodge any debris from underneath the keys.
Blow under the keys again with the canned air to remove any remaining detritus.
Pop off individual keys with a knife or similar object, then put them in a small bowl with a couple of drops of dish soap for hand washing. Leave the space bar and other larger keys intact--they can be very difficult to replace.
Remove the keyboard from the laptop if it's still not functioning properly opr if you've had a major spill or other accident. The procedure for keyboard removal is different, depending on the manufacturer; check the documentation of your laptop to see how it's done.
Wipe down the keyboard down with rubbing alcohol and a lint-free cloth to clean it--after you've removed it from the laptop, A microfiber cloth or one made specifically for electronics is best. Let everything dry thoroughly.
Plug the keyboard back into the laptop, and replace any keys you've removed. Make sure all connections are seated solidly.
Be aware that a can of compressed air contains a toxic chemical as well as air. Handle it carefully and never hold the can upside down. Tilt it at an angle two or three inches away from your keyboard as you direct the air between the keys