Consider reversing a flashlight battery, the easiest one to get to and turn around, to cut the electrical circuit during storage.
Bare in mind that when you try to use the torch, it won't work. You'll have to remember what you did, which may be difficult if several years have gone by ....
Recall is not difficult if last-battery-reversal is your invariable habit - and the non-working "torch" should be a reminder. Switching the last battery around should not normally be a big challenge, though I concede if an emergency has disabled one hand-arm you now have two problems.
In a power outage situation, hopefully you have deployed one or more of the rechargeable emergency lights that only come on when power goes out.