May I suggest against setting traps or poisons for two valid reason
1) most rodents (especially rats) are neophobes and would be extremely wary of any recent change to their environment
2) wouldn’t your ‘womenfolk’ get rather suspicious if they found out that you had developed a recent obsession with buying mouse-traps and peering into dark, quiet places and crooning ‘here mousey, I won’t hurt you (much)’
What I would suggest is this; find the little blighter’s home, because it will only get worse if it turns out that the little interloper was an expectant mother, and see if you can forcibly evict your unwanted tenant. If that fails then lockdown on all possible sources of food and starve the b45tard out, make sure to clean up any leftover or stray bits of food, it may be slow but hopefully it would be less obvious than rampaging through the house wielding a sledgehammer and leaving peanut butter everywhere.
Oh and if possible find out how the bu99er got in, otherwise one day you might find that you’re up to your neck in mice