ugh, i live in the country, so we get the occasional mouse. we actually just got rid of one a couple weeks ago.
you CAN call an exterminator, but it’s not really necessary. they’ll just set out poison/traps, which you’ve already done.
we’ve never used poison, but if you want to try going that route, i believe there’s a type of poison that will kill the mouse in a way that it won’t stink up your house as it decomposes. my uncle had a dead mouse/rat in his walls and the smell was awful, so you definitely don’t want to deal with that.
as far as traps go, we haven’t had much luck with glue traps. we usually use the snap traps. but if you have pets or young children in your home, you have to be careful that they don’t touch/step on them. my brother lost a shoe to a glue trap and i’ve had to rescue two cats from them, so yeah…not fun! most recently we used a live capture trap in addition to a snap trap and we caught the mouse in the live trap within 2 days and set it loose outside.
for bait, we had always used peanut butter, but our exterminator happened to drop by for his monthly visit during the mouse’s visit and he said to use nutella, so that’s what we used this last time.
if you can, try to find the hole(s) where the mouse comes/goes or the area of the house that it seems to lurk in (usually the kitchen, but we had a mouse once that liked my room, unfortunately) and set the traps in that area. you can lookout for its droppings to tell you where it’s been- they look like tiny black specks. you’ve probably done this already, but check cereal boxes and stuff like that to see if the mouse has been digging into your food and don’t leave any food wrappers, dirty dishes, etc sitting out (my brother was horrible about leaving food around, so it was no surprise when he found a mouse in his room).
i know how unnerving it is knowing there’s a little critter loose in your home. it’s the worst when you can hear it, but can’t see it, lol! anways, good luck. hopefully, between the traps and your cat, your house will be mouse-free again soon!