I have a POE/IP 5MP 'covert' camera 'made by' GW Security that is hidden inside of a PIR sensor type enclosure, that has worked well, but after five years in use, it's given up the ghost. This particular camera does not seem to be available any more, but of course Amazon has a number of cameras I could potentially choose from.

Does anyone have any suggestions for a similar camera that is 4MP minimum, integrated microphone would be nice but not required, that I could replace it with? Or should I just throw a dart at the Amazon listings?

I use these but you would have to "covert" them. I have one mounted behind a 3/16 hole. The added mic is outstanding.
https://www.amazon.com/Revotech-Indoor- ... FM5Z9?th=1
This Aliexpress site also has fisheye and true pinhole units that work well.
https://www.aliexpress.com/store/110054 ... bQxZbQxZm2

I bought a couple with built in audio and it is ok but does not compare to those with the extenal "yellow" mic.
The ING store also has one like your old one and has IR lights. The above units do not have IR. I have never had a problem with this Ali store other than not watching closely to what I was ordering.

https://www.aliexpress.us/item/32568051 ... pt=glo2usa

Here are examples from my various styles

To be honest, I would look at replacing the camera board that is inside the PIR box. The Camera that you have in there now at one time came with some Stats about the Image size and I would look for a replacement camera with same or almost same specs and replace the Module. Things like 1/3" 5MP CMOS Sensor, 5MP 2592*1944@15fps;4MP 2592*1520@30fps and so on. Keep in mind that the good ones and I am guessing yours would be as well, would have a 940nm LED and not the 850 type. So it is important to find out if the board you are going to replace it with will have the right type IR. 850 like what is in a normal B/W camera at night you can see the red leds when they are in the 940's we can't see and that is why it is important that your new camera board would have image type and size so you can connect it to the Lens in the hidden PIR body and that it has the ability to use 940 IR because most 850's won't detect the 940 leds when on.. Also it has been a while but last time I looked on E Bay they had some that is an upgrade to the type I own where the new ones offer ONVIF, RTSP, p2p and POE so they have moved a long way since my 1.3mp PIR hidden camera came out..

Thanks for the info. Those Revotech cameras seem to have pretty good image quality.

I'll have to take this one apart and see exactly what's inside and if I can find a replacement to just fix/rebuild this one. If memory serves, it's 940nm version, but as it's not functioning now and I've never really paid attention to it, I'm not positive. Maybe it'll say on the LED board.