I am wanting to add two new outlets on a unfinished wall in my garage. This wall currently has no outlets at all and is a exterior facing wall. I was wondering if i can tie into the outlet in the ceiling that is used for my garage door opener. I believe this outlet is on the same circuit as all other outlets in my garage. I don't plan on running a lot of devices at the same time, just need the extra outlets for ease of use on that side of the garage. I have never had a breaker trip in the garage either. I am wondering if this is allowed? It is the nearest outlet that i can tie into and it would be very easy to do as well. These would be two 15 amp outlets and would be used for light use.
You may be violating code - we don't know the breaker size or the wire gauge to your garage. Also, you'll know you've got too much loaded on there if the breaker flips every time you try to open or close your garage door.
But short answer is yes, you can. Just install it properly (tons of youtube videos).