This typically happens when products are broadcasting on the same frequency. If your neighbor has a similar product that sends a wireless signal out on the same frequency as your receiver, there's a possibility it could activate it.
This is an easy fix. Most products will have “privacy codes,” either in the form of dip switches or small wire loops, located on the back of the product or inside the cover of the product. To change the privacy code you need to snip any wire loop or combination of wire loops. If your product does not have wire loops, it probably has dip switches.
Changing the privacy code on a product, whether it is a receiver or a button will change the operating frequency of that product. If you have a button and a receiver, for example, you MUST change the privacy code on both products or else they won't be able to communicate with each other.
Here's an example: If you snip the 1st wire on the push button, you have to snip the 1st wire on the receiver. If you snip wire 1 and 3 on the receiver you must snip 1 and 3 on the button or else they will no longer communicate with each other.