Hi,
Has it gotten wet at all?
It may be that either the touchpad is failing or perhaps it is touching on the systemboard below causing the random events.
I had this problem with my Lenovo laptop and had to place a piece of thin insulating material between it and the systemboard to stop it from happening.
Here’s the [http://h10032.www1.hp.com/ctg/Manual/c03565466|hardware maintenance manual] for the laptop.
It will help you disassemble the laptop so that the touchpad connections etc can be checked. Go to p.124 to see the necessary pre-requisite steps and then the procedure to remove the systemboard. You may not have to remove the board but this lets you at least check the touchpad connections etc.
If you have to replace the touchpad you have to basically disassemble the entire laptop as it is part of the top cover assembly. Go to p.36 Item #3 to find the top cover part number applicable to your model variant. If you search online using the ''part number only'' you’ll get results for suppliers of the part.