battery will drain in 2/3 days when car not in use. where do u start looking
First step is verify the battery is good as a shaky battery can deplete itself quickly.
Next step is to use a test light or VOM (preferably the latter) and connect it between the battery negative terminal and the now disconnected negative battery cable. A substantial current draw should illuminate the light or show the current draw in Milliamperes on the VOM.
One then starts unplugging and installing one fuse at a time until the light goes out or the MAs drop to an acceptable level. Once you find the problem circuit then you have to start narrowing that area down by process of elimination…
Be sure to check the trunk light and make sure that it’s off. Like the refrigerator you never really know… 
+1 for ok4450.
+2 for OK4450’s post.
A quick way to determine if a trunk, glove box, or under hood light is staying on is, quickly open each compartment and touch the bulb.
If the bulb is hot it’s been on for a while.
Tester