My wife and I have a plan that we have agreed on. Part of that plan is that we have previously agreed upon safe word. Not...'It's me' or 'Hi honey I'm home' but a word or phrase that no-one will guess. Especially if your husband is prone to coming in and out of the house at strange times of the night (shift work, call outs etc).
Hopefully you will never need it, but it can't hurt to have one.
