10 silent signs your house has a major electrical problem
Many electrical appliances generate heat during operation. However, the outlet itself should never get hot. If you notice heat at an outlet, immediately unplug any cords and do not use the outlet until you can troubleshoot the issue.
Switch cover plates should be treated in the same way, with one exception: Dimmer switches commonly get warm to the touch, since they are dissipating the excess electrical energy in order to create the dimming effect. However, even dimmer switch cover plates should never be uncomfortably hot to the touch. Excess heat is why you should always check the wattage before you install a dimmer switch.