Yesterday the trunk on my 2001 IS300 (parked in my garage) apparently opened on its own for the first time, but I attributed it to operator error. Closed trunk & drove off. Today I didn't drive it at all and late in the day found the trunk open again and the battery dead. I tried to lock it so it would only open with master & not valet key, but the inside trunk release beside the driver's seat will still pop it. As far as I know the master key fob switch would open it -- never had a problem before -- but am not sure since I have no battery power until I get AAA out here. I can't think of anything that's changed except my next door neighbor just installed a new keypad for her garage door opener, and it was used just before the first unexpected opening. Seems crazy that it could be opening my trunk, but is this possible? Any other thoughts or fixes??? Thanks in advance!

the alarm , key fob or button /wiring is shorting and causing it to open.