It was an okay listen to actors who didn't frequent CBSRMT very often (or only this time).  Definitely some plot holes as Mike pointed out - why didn't they just leave when she didn't appear to have a gun early on?  If she had it on her, wouldn't it have been fairly easy to overpower her?  If she had escaped, wouldn't they do more than call, wouldn't they come visit?  I agree with Mike again that between burning and being shot why didn't they all just rush her at the same time?  Although phones do use two twisted pair wires, usually it's four that come into a house (I'm not sure if it was the same then, but I don't know why it would be three - perhaps because then there would only be 6 combinations instead of 24 for the story).

All that said, I wasn't sure who was craziest until Act 2 as others mentioned.