I'm not sure if this is what you want but there are devices for people with hearing disabilities that will flash a light if a phone call comes in. Versions exi

I'm not sure if this is what you want but there are devices for people with hearing disabilities that will flash a light if a phone call comes in. Versions exist for both land lines and for cell phones, for example: https://www.maxiaids.com/cell-phone-sensor https://www.maxiaids.com/cell-phone-sensor